Question

Find the magnitude of angle A, if :
(1) 2 sin A cos A - cos A-2 sin A+1=0​

Answer 1

2SINA.SIN(90-A)=SIN(90-A+2)SINA+1

AS SIN IS Common EVERYWHERE WE WILL COMPARE THE ANGLES

2(90-A)=(90-A+2)A+1

180-2A=90A+90-A²-A+2A+2

88=91A-A²

-A²+91A-88=0

BY QUADRATIC FORMULA

A=0.97 & 90

SO MAGNITUDE OF A IS EITHER 1 OR 90

(0.97=1)