1. (i) (2 tan 30°)/(1 - tan²30°) Putting the value of each trigonometric ratios, we get (2(1/√3))/(1+(1/√3)²) = (2/√3)/(1 + 1/3) = (2/√3)/(4/3) = (6)/(4√3) = √3/2 We know that sin 60° =Y hence the option (A) is correct. (ii)(1 - tan² 45°)/(1 + tan² 45°) Putting the value of each trigonometric ratios, wRead more

    (i) (2 tan 30°)/(1 – tan²30°)
    Putting the value of each trigonometric ratios, we get
    (2(1/√3))/(1+(1/√3)²) = (2/√3)/(1 + 1/3) = (2/√3)/(4/3) = (6)/(4√3) = √3/2
    We know that sin 60° =Y hence the option (A) is correct.

    (ii)(1 – tan² 45°)/(1 + tan² 45°)
    Putting the value of each trigonometric ratios, we get
    (1-(1)²)(1+(1)²) = (1-1)/(1+1) = 0/2 = 0
    Hence, the option (D) is correct.

    (iii) sin 2A = 2 sin A
    We know that sin 0 = 0, hence, the option (A) is correct.

    (iv) (2 tan 30°)/(1 – tan²30°)
    Putting the value of each trigonometric ratios, we get
    (2(1/√3))/(1-(1/√3)²) = (1/√3)/(1 – 1/3) = (2/√3)/(2/3) = 3/√3 = √3
    We know that tan 60° = √3, hence, the option (C) is correct.

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  2. (i) tan 48° tan 23° tan 42° tan 67° = 1 LHS = tan 48° tan 23° tan 42° tan 67° = tan 48° tan 23° cot(90°-42°) cot(90°-67°) [∵ cot(90°-θ) = tanθ] = tan 48° tan 23° cot 48° cot 23° = tan 48° tan 23° × 1/tan 48° × 1/tan 23° = 1 = RHS (ii) cos 38° cos 52° - sin 38° sin 52° = 0 LHS = cos 38° cos 52° - sinRead more

    (i) tan 48° tan 23° tan 42° tan 67° = 1
    LHS = tan 48° tan 23° tan 42° tan 67°
    = tan 48° tan 23° cot(90°-42°) cot(90°-67°) [∵ cot(90°-θ) = tanθ]
    = tan 48° tan 23° cot 48° cot 23°
    = tan 48° tan 23° × 1/tan 48° × 1/tan 23°
    = 1 = RHS
    (ii) cos 38° cos 52° – sin 38° sin 52° = 0
    LHS = cos 38° cos 52° – sin 38° sin 52°
    = cos 38° cos 52° – cos (90°-38°) cos (90°-52) [∵ cos (90°-0°) = sinθ]
    = cos 38° cos 52° – cos52° – cos 38°
    = 0 = RHS

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  3. Let, p(x) = ax³ + bx² + cx + d be a cubic polynomial whose zeroes taken two at a time, and the product of its zeroes as 2, -7, -14 respectively. Given that, α + β + γ = 2 αβ + βγ + γα = -7 αβγ = -14 We know that, α + β + γ = -(Cofficient of x²)/(Cofficient of x³) αβ + βγ + γα = (Cofficient of x)/(CoRead more

    Let, p(x) = ax³ + bx² + cx + d be a cubic polynomial whose zeroes taken two at a time, and the product of its zeroes as 2, -7, -14 respectively.
    Given that,
    α + β + γ = 2
    αβ + βγ + γα = -7
    αβγ = -14
    We know that,
    α + β + γ = -(Cofficient of x²)/(Cofficient of x³)
    αβ + βγ + γα = (Cofficient of x)/(Cofficient of x³)
    αβγ = -(Constant term)/Cofficient of x³)
    Therefore,
    α + β + γ = -(Cofficient of x²)/(Cofficient of x³) = (-b)/a = 2/1
    αβ + βγ + γα = (Cofficient of x)/(Cofficient of x³) = c/a = (-7)/1
    αβγ = -(Constant term)/Cofficient of x³) = (-d)/a = (-14)/1
    On comparing, a = 1, b = -2, c = -7 and d = 14
    Hence, the required cubic polynomial is p(x) = x³ – 2x² – 7x + 14.

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  4. We know that, Sum of zeroes = -(Cofficient of x²)/Cofficient of x³) Therefore, (a - b) + a + (a + b) = (-(-3))/1 ⇒ 3a = 3 ⇒ a = 1 Product of zeroes = -(Constant term)/(Cofficient of x³) Therefore, (a - b)(a)(a + b) = -(1)/1 ⇒ (1 - b)1(1 + b) = -1 [Because a = 1] ⇒ 1 - b² = - 1 ⇒ b² = 2 ⇒ b = +- √2 HRead more

    We know that,
    Sum of zeroes = -(Cofficient of x²)/Cofficient of x³)
    Therefore,
    (a – b) + a + (a + b) = (-(-3))/1
    ⇒ 3a = 3
    ⇒ a = 1
    Product of zeroes = -(Constant term)/(Cofficient of x³)
    Therefore,
    (a – b)(a)(a + b) = -(1)/1
    ⇒ (1 – b)1(1 + b) = -1 [Because a = 1]
    ⇒ 1 – b² = – 1
    ⇒ b² = 2
    ⇒ b = +- √2
    Hence, a = 1 and b = +- √2

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  5. The zeroes of a polynomial are the values of the variable that make the polynomial equal to zero. The zeroes of a polynomial are also sometimes called the roots of the polynomial. Zeroes can also be used to factor polynomials, which can simplify equations and make them easier to solve. Here is the SRead more

    The zeroes of a polynomial are the values of the variable that make the polynomial equal to zero. The zeroes of a polynomial are also sometimes called the roots of the polynomial. Zeroes can also be used to factor polynomials, which can simplify equations and make them easier to solve.

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