Question

if sin^2A+3cosA=2 then what is the value of cos^3A+sec^3A=?

Answer 1

Let A=90 thenPut the value of A in your questionSin(90*3)*sin^3 90 + cos(90*3)*cos^3 90=-1*1+0*0 =-1Now RHS COS^3 2A COS^3(2*90)COS^3(180)=(-1)^3 =-1 HENCE Proved