Q. 8cos^3(20) - 8sin^3(10) - 6cos20 + 6sin10 = 2

SUBSCRIBE TO OUR NEWSLETTER
You May Also Like
11. Find the number of geometric means inserted between 1 and 243 in which the ratio of the first mean to the last mean is 1:27. Soln: ...
Q. If f(x) = x^2 – 2x, g(x) = 2x + 3 and fg-1(x) = 3 then find the value of x. Soln: To find g-1(x), Let y be the image of x under g, then y = 2x + 3 x = (y – 3)/2 Interchanging the role of x and y, we ha ...
Q. If 2Tanα = 3Tanβ, then show that Tan(α-β) = Sin2β/(5-Cos2β) Soln: 2tanα=3tanβ tanα=(3/2)tanβ L.H.S. = tan(α-β) = (tanα-tanβ)/(1+tanα.tanβ) = {(3/2)tanβ-tanβ}/{1+(3/2)tanβ.tanβ} = ...
Q. The inverse of the function f(x)=ax+b, x∈R is f-1(x)=8x-3. Soln: Here, f(x) = ax + b Let y be the image of x under f, then y = ax + b x = (y-b)/a Interchanging the role of x and y ...
Q. Prove that: 4(cos^4A+sin^4A)/(cos^4A-sin^4A)=(3+cos4A)Sec2A ...