Question

what is the exact, fractional value of sin75

Answer 1

sin (30+45)

Answer 2

so then use sum/difference formula

Answer 3

what is the sum/difference formula?

Answer 4

gj light! thats the hardest past coming up with two numbers that =75 that have exact answers

Answer 5

so sin30cos45+cos30sin45

Answer 6

http://www.mathwords.com/s/sum_difference_identities.htm to strive5

Answer 7

sin(x+y)=sinxcosy+sinycosx
sin(x-y)=sinxcosy-sinycosy
cos(x+y)=cosxcosy-sinxsiny
cos(x-y)=cosxcosy+sinxsiny

Answer 8

take it from there

Answer 9

thank you that was just on the A2 Trig regents i took today and i had no idea how to do it

Answer 10

doesnt sound like A2 to me
more like actual trig

Answer 11

there were a lot of weird questions on this regents. it was a lot harder than the past regents that i took as practice.

Answer 12

fyi the answer is (sqrt(2)+sqrt(6))/4

Answer 13

i think i put sqrt(2)/4 just from trying to do it with no idea of the actual formula. i might get some credit. it was a 4 point question