If 0<=k< Pi/2 and the area under the curve y = cosx from x= K to x= pi/2 is 0.1, then k=...?

Answer 1

Int(k,pi/2) cox dx = 1-sink =0.1 so sin k = 0.9 and k=1.12 rad

Answer 2

You need to find the integral between pi/2 and k of cosx in terms of k. Equate this to 0.1 and solve the equation. You will need a calulator to give inverse trig. value as its not a simple one.