Question

Find the exact value using asum or difference identity.tan (-15°)[?]+Hint: tan(A + B)tan Atan B1 F tan A tan B

Answer 1

1. Calculate tan(-15):

we will use tan( -) = (tan -tab)/(1+tan *tan )

so, tan (45-60) = (tan 45 -tan 60) /(1+ tan45 *tan 60)

= (1 -√3 )/1+1*√3

rationalize = (1-√3)/(1+√3 )* (1+√3/1+√3)

= -2 +√3

The answer = -2 +√3