SOLUTION: Use a sum or difference formula to find the exact value of the following
Cos13pie/30 cos2pie/5 - sin13pie/30 sin2pie/5
Algebra.Com
Question 1036267: Use a sum or difference formula to find the exact value of the following
Cos13pie/30 cos2pie/5 - sin13pie/30 sin2pie/5
Answer by Cromlix(4381) (Show Source): You can put this solution on YOUR website!
Hi there,
cos13π/30 cos2π/5 - sin13π/30 sin2π/5
= cos(13π/30 + 2π/5)
Take to common denominator = 30
= cos((13π+12π/30)
= cos(25π/30)
= cos (5π/6)
Hope this helps :-)
RELATED QUESTIONS
Use a sum or difference formula to find the exact value of the following:
{{{... (answered by lwsshak3)
Use a sum or difference formula to find the exact value of the following.
cos 2(pi)/5... (answered by ikleyn)
Use a sum or difference formula to find the exact value of cot... (answered by lwsshak3)
Use a sum or difference formula to find the exact value of the following.... (answered by lwsshak3)
Use a sum or difference formula to find the exact value of the following.
cos 7pi/10... (answered by lwsshak3)
Use a sum or difference formula to find the exact value of the following.
{{{... (answered by ikleyn)
Use a sum or difference formula to find the exact value of the following.... (answered by ikleyn)
Use a sum or difference formula to find the exact values of the following.... (answered by robertb)
use sum or difference formula to find exact value of the following:... (answered by Edwin McCravy)