Sign Up


Have an account? Sign In Now

Sign In


Forgot Password?

Don't have account, Sign Up Here

Forgot Password

Lost your password? Please enter your email address. You will receive a link and will create a new password via email.


Have an account? Sign In Now

You must login to ask question.


Forgot Password?

Need An Account, Sign Up Here

You must login to ask question.


Forgot Password?

Need An Account, Sign Up Here
Sign InSign Up

Discussion Forum

Discussion Forum Logo Discussion Forum Logo

Discussion Forum Navigation

    • NCERT Solutions
    • MCQ Online Test
    • हिंदी मीडियम
Search
Ask A Question

Mobile menu

Close
Ask a Question
  • NCERT Solutions
  • MCQ Online Test
  • हिंदी मीडियम

rishab17

Ask rishab17
7Followers
2Questions
Home/ rishab17/Best Answers
    • About
    • Questions
    • Polls
    • Answers
    • Best Answers
    • Followed Questions
    • Favorite Questions
    • Groups
  1. Asked: October 29, 2020In: Class 10

    A box contains 90 discs which are numbered from 1 to 90. If one disc is drawn at random from the box, find the probability that it bears (i) a two-digit number (ii) a perfect square number (iii) a number divisible by 5.

    rishab17
    Added an answer on February 28, 2023 at 7:16 am

    Total number of discs = 90 (i) Total number of two-digit numbers between 1 and 90 81 P (getting a two-digit number) = 81/90 = 9/10 (ii) Perfect squares between 1 and 90 are 1,4,9, 16, 25, 36, 49, 64, and 81. Therefore, total number of perfect squares between 1 and 90 is 9. P (getting a perfect squarRead more

    Total number of discs = 90
    (i) Total number of two-digit numbers between 1 and 90 81
    P (getting a two-digit number) = 81/90 = 9/10
    (ii) Perfect squares between 1 and 90 are 1,4,9, 16, 25, 36, 49, 64, and 81.
    Therefore, total number of perfect squares between 1 and 90 is 9.
    P (getting a perfect square) = 9/90 = 1/10
    (iii) Numbers that are between 1 and 90 and divisible by 5 are 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 55, 60, 65, 70, 75, 80, 85, and 90.
    Therefore, total numbers divisible by 5 = 18
    Probability of getting a number divisible by 5 = 18/90 = 1/5

    See less
    • 1
    • Share
      Share
      • Share on Facebook
      • Share on Twitter
      • Share on LinkedIn
      • Share on WhatsApp
  2. Asked: February 16, 2023In: Class 10 Maths

    State whether the following are true or false. Justify your answer.

    rishab17
    Added an answer on February 17, 2023 at 9:55 am

    (i) False, Let A = 30° and B = 60° Therefore, LHS = sin(A + B) = sin(30° + 60°) = sin 90° 1 and RHS = sin A + sin B = sin 30° + sin 60° = 1/2 + √3/2 = (1+√3)/2 ≠ 1 Hence, sin (A + B) ≠ sin A + sin B (ii) True, As we know that sin 0° = 0, sin 30° = 1/2, sin 45° = 1/√2, sin 60° = √3/2 and sin 90° = 1Read more

    (i) False,
    Let A = 30° and B = 60°
    Therefore, LHS = sin(A + B) = sin(30° + 60°) = sin 90° 1 and
    RHS = sin A + sin B = sin 30° + sin 60° = 1/2 + √3/2 = (1+√3)/2 ≠ 1
    Hence, sin (A + B) ≠ sin A + sin B

    (ii) True,
    As we know that sin 0° = 0, sin 30° = 1/2, sin 45° = 1/√2, sin 60° = √3/2 and sin 90° = 1
    Hence, for the increasing values of θ, sin θ is also increasing.

    (iii) False,
    As we know that cos 0° = 1, cos 30° = √3/2, cos 45° = 1√2, cos 60° = 1/2 and cos 90° = 0
    Hence, for the increasing values of θ, cos θ is decreasing.

    (iv) False,
    ∵ cos 30° = √3/2, but sin 30° = 1/2.

    (v) True,
    ∵ tan 0° = 0, we know that cot 0° = 1/tan 0° = 1/0, which is not defined.

    See the explanation video of the above solution here✌

    See less
    • 3
    • Share
      Share
      • Share on Facebook
      • Share on Twitter
      • Share on LinkedIn
      • Share on WhatsApp
  3. Asked: February 16, 2023In: Class 10 Maths

    Evaluate the following trigonometry questions?

    rishab17
    Added an answer on February 17, 2023 at 9:55 am

    (i) (sin 18°)/(cos 72°) = (sin 18°)/(cos 72°) = cos (90° - 18°))/(cos 72°) [∵ cos (90° - θ) = sin θ] = (cos 72°)/(cos 72°) = 1 (ii) (tan 26°)/(cot 64°) = (tan 26°)/(cot 64°) = (cot (90° - 26°))/(cot 64°) [∵ cot (90° - θ) = tan θ] = (cot 64°)/(cot 64°) = 1 (iii) cot 48° – sin 42° = cot 48° – sin 42°Read more

    (i) (sin 18°)/(cos 72°)
    = (sin 18°)/(cos 72°) = cos (90° – 18°))/(cos 72°) [∵ cos (90° – θ) = sin θ]
    = (cos 72°)/(cos 72°) = 1

    (ii) (tan 26°)/(cot 64°)
    = (tan 26°)/(cot 64°) = (cot (90° – 26°))/(cot 64°) [∵ cot (90° – θ) = tan θ]
    = (cot 64°)/(cot 64°) = 1

    (iii) cot 48° – sin 42°
    = cot 48° – sin 42° = cos 48° – cos (90° – 42°) [∵ cos (90° – θ) = sin θ]

    (iv) cosec 31° – sec 59°
    cosec 31° – sec 59° = cosec 31° – cosec (90° – 59°) [∵ cosec (90° – θ) = sec θ]
    = cosec 31° – cosec 31° = 0

    See here for video explanation for this question😮👇

    See less
    • 3
    • Share
      Share
      • Share on Facebook
      • Share on Twitter
      • Share on LinkedIn
      • Share on WhatsApp
  4. Asked: December 31, 2020In: Class 10 Maths

    Find the zeroes of the following quadratic polynomials and verify the relationship between the zeroes and the coefficients. 6x² – 3 – 7x.

    rishab17
    Added an answer on January 4, 2023 at 3:55 am

    6x² - 3 - 7x = 6x² - 7x - 3 = 6x² - 9x + 2x -3 = 3x(2x - 3) + 1(2x -3) = (3x +1)(2x -3) The value of 6x² - 7x - 3 is zero if 3x + 1 = 0 or 2x -3 = 0. ⇒ x = -1/3 or x = 3/2, Therefore, the zeroes of 6x² - 7x - 3 are -1/3 and 3/2. Now, Sum of zeroes = -1/3 + 3/2 = (-2 + 9)/6 = 7/6 = -(7)/6 = -(CofficiRead more

    6x² – 3 – 7x
    = 6x² – 7x – 3
    = 6x² – 9x + 2x -3
    = 3x(2x – 3) + 1(2x -3)
    = (3x +1)(2x -3)
    The value of 6x² – 7x – 3 is zero if 3x + 1 = 0 or 2x -3 = 0.
    ⇒ x = -1/3 or x = 3/2,
    Therefore, the zeroes of 6x² – 7x – 3 are -1/3 and 3/2.
    Now, Sum of zeroes = -1/3 + 3/2 = (-2 + 9)/6 = 7/6 = -(7)/6 = -(Cofficient of x)/Cofficient of x²
    Product of zeroes = (-1/3) x 3/2 = -1/2 = (-3)/6 = Constant term/Cofficient of x².

    See here 😎

    See less
    • 1
    • Share
      Share
      • Share on Facebook
      • Share on Twitter
      • Share on LinkedIn
      • Share on WhatsApp
  5. Asked: December 28, 2020In: Class 10 Maths

    Find the zeroes of the following quadratic polynomials and verify the relationship between the zeroes and the coefficients. x² – 2x – 8.

    rishab17
    Added an answer on January 3, 2023 at 11:28 am

    x² - 2x - 8 = x² - 4x + 2x - 8 = x(x - 4) + 2(x - 4) = (x + 2)(x - 4) The value of x² - 2x - 8 is zero if x + 2 = 0 or x - 4 = 0 x = -2 or x = 4 Therefore, the zeroes of x² - 2x - 8 are -2 and 4. Now Sum of zeroes = -2 + 4 = 2 = -(-2)/1 =-(Cofficient of x)/(Cofficient of x²) Product of zeroes = (-2)Read more

    x² – 2x – 8
    = x² – 4x + 2x – 8
    = x(x – 4) + 2(x – 4)
    = (x + 2)(x – 4)
    The value of x² – 2x – 8 is zero if x + 2 = 0 or x – 4 = 0
    x = -2 or x = 4
    Therefore, the zeroes of x² – 2x – 8 are -2 and 4. Now
    Sum of zeroes = -2 + 4 = 2 = -(-2)/1 =-(Cofficient of x)/(Cofficient of x²)
    Product of zeroes = (-2) x 4 = -8 =-8/1 = (Cofficient term)/Cofficient of x²)

    Video Explanation 👇

    See less
    • 1
    • Share
      Share
      • Share on Facebook
      • Share on Twitter
      • Share on LinkedIn
      • Share on WhatsApp
1 2 3 4 5 6 7

Sidebar

Ask A Question

Subscribe

  • Popular
  • Answers
  • Mrinal Garg

    Which is the best website providing NCERT Solutions?

    • 116 Answers
  • Richa

    NCERT Books

    • 31 Answers
  • manishq1

    Where can I get NCERT books in PDF format?

    • 26 Answers
  • Richa

    NIOS

    • 15 Answers
  • Richa

    NCERT Solutions

    • 12 Answers
  • Piyush365
    Piyush365 added an answer King Bruce was feeling despair due to his repeated failures… May 8, 2025 at 11:54 am
  • Piyush365
    Piyush365 added an answer The spider climbed a thin, silken thread to reach its… May 8, 2025 at 11:54 am
  • Piyush365
    Piyush365 added an answer The spider’s home was its cobweb, which was a delicate… May 8, 2025 at 11:54 am
  • Piyush365
    Piyush365 added an answer There is a clear resemblance between King Bruce’s and the… May 8, 2025 at 11:54 am
  • Piyush365
    Piyush365 added an answer The poet calls the spider “brave” because it continues to… May 8, 2025 at 11:54 am

Explore

  • Home
  • Questions

© 2025 Tiwari Academy. All Rights Reserved