SOLUTION: Using the fact that the exact values of sin 45 and cos 45 are (sqrt(2))/2, and the exact values of sin 30 and cos 30 are respectively 1/2 and (sqrt(3))/2 find the exact value of si

Question 533520: Using the fact that the exact values of sin 45 and cos 45 are (sqrt(2))/2, and the exact values of sin 30 and cos 30 are respectively 1/2 and (sqrt(3))/2 find the exact value of sin 75
Answer by lwsshak3(11628) (Show Source): You can put this solution on YOUR website!
Using the fact that the exact values of sin 45 and cos 45 are (sqrt(2))/2, and the exact values of sin 30 and cos 30 are respectively 1/2 and (sqrt(3))/2 find the exact value of sin 75
**
Use addition formula for sin:
sin(s+t)=sin s cos t + cos s sin t
sin(75�)=sin(45�+30�)=sin45cos30+cos45sin30
sin(75�)=√2/2*√3/2+√2/2*1/2
sin(75�)=√6/4+√2/4=(√6+√2)/4
..
check: (with calculator)
sin 75�≈.9659
(√6+√2)/4≈.9659
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