Question

Please solve
This questions

Answer 1

Final. Answer :
$\frac{3}{ \sqrt{10} }$
Understanding required :
1) sin ^-1(x) + cos^-1(x) = π/2
2) sin(A+B) = sinA cosB + cosA sinB
3) sin^2(a) + cos^2(a) = 1


For Calculation see pic.

Answer 2

In the attachments I have answered this problem.

In the 3rd attachment I have listed the formula which I used in this problem.

See the attachment for detailed solution