Originally Posted by Joker
Expand that using the 'sum or difference' formula for sine.
Pythagoras' theorem: If , then ...
2. If tanX = -3/4 and 90<x<180, find cosX (the 90 and 180 are degrees)
3. If (tanX)(cscX) = 3, find value of cosX
Write in terms of and and use the identity .
4. If tanX= 3/4 and 180<X<270, find the exact value of sin2X
Write , use the 'sum-difference' formulas on both the
5. Find the value of tan(A+b) if cosA = 13/5, tanB = 3/4, and 0<A<90
numerator and the denominator, and write in terms of sine and cosine.