If Cos 21=m, determine without the use of calculators, the value of the following in terms of m: I) tan 21 and 2) sin66

Question

Solve for tan 21 and sin 66

Answer 1

you can determine sin 21^o by using the Pythagorean identity.

You can then determine tan 21^o by computing the ratio of sine to cosine for said angle; these will be in terms of m.

 

for sin 66^o I would just use a calculator to get a good 5-decimal place approximation!