Question

show that cos2(45+A)+cos2(45-A)/tan(60+A)×tan(30-A)=1​

Answer 1

Answer:

Step-by-step explanation:

cos^2(45 + theta) + cos^2(45 - theta) / tan(60 + theta) tan(30 - theta) = 1

LHS =cos^2(45 + theta) + sin^2{90 - (45 -theta)} / tan(60 + theta) cot{90 - (30 - theta)}

=cos^2(45 + theta) + sin^2(90 - 45 + theta) / tan(60 + theta) cot(90 - 30 + theta)

=cos^2(45 + theta) + sin^2(45 + theta) / tan(60 + theta) cot(60 + theta)

= 1 / 1

LHS = 1 = RHS

Hence proved.