Question

Sin^3a+cos^3 A\
1-2cos^2A= sec a- sin a/tan a

Answer 1

Answer:

2tan3Acos3A−tan3A+1=2cos3A

2tan3Acos3A−tan3A−2cos3A+1=0

tan3A(2cos3A−1)−1(2cos3A−1)=0

(tan3A−1)(2cos3A−1)=0

Either tan3A−1=0 or 2cos3A−1=0

tan3A=1 or cos3A= 1/2

tan3A=tan45 or cos3A=cos60

3A=45 or 3A=60

A=15

or A=20

Thus, A=15

or20°