Question

28. If 7 sin^2 theta + 3 cos^2 theta = 4, 0° < theta < 90°, then find the value of theta​

Answer 1

Answer:

7sin^2 theta+ 3cos^2 theta =4

7sin^2 theta + 3 ( 1-sin^2) =4

7sin^2 theta +3 - 3sin^2=4

4sin^2 +3=4

sin^2=1/4

sin theta=1/2.

Now theta is acute.

So sin theta =1/2=sin 30

theta=30 deg