Hello, jamespk07!
You're expected to know some standard trig values . . .
Prove: .
. . . . . . .
. . . . . . .
. . . . . . . .
. . . . . . . .
Umm the question is
sin(3pi-x) = sinx
well i figured to use the sum and difference formulas but after i change it to the formula i get stuck... and i dont know where elso to go
same with these other ones-
cos(5pi/4-x) = square root of -2/2(cos x + sin x)