Question

what is the value of ten15

Answer 1

Answer.

Let  tan(15°) = tan(45°-30°)

We know that tan(A - B) = (tanA - tanB) /(1 + tan A tan B)

⇒tan(45°-30°) = (tan45°- tan30°)/(1+tan45°tan30°)

= {1- (1/√3)} / {1+(1/√3)}

∴ tan15° = (√3 - 1) / (√3 + 1)

Answer 2

I suppose the question to be Tan15°

We know that ,
sin15°=√3-1/2√2

cos15°=√3+1/2√2

Now tan15=sin15/cos15=√3-1/√3+1

After rationalising the denominator

tan15=4-2√3/2=2-√3

Value of tan15= 2-√3