sin7x-sin6x+sin5x
Until an "equals" sign shows up somewhere in the expression, there's nothing to prove.
Do sin(x), square it, and then multiply it by two.
No, (sinx)^2 + (cosx)^2=1 is though
1
sin7x-sin6x+sin5x
Until an "equals" sign shows up somewhere in the expression, there's nothing to prove.
Well, darling, if we square the first equation and the second equation, add them together, and do some algebraic magic, we can indeed show that a squared plus b squared equals 89. It's like a little math puzzle, but trust me, the answer is as sassy as I am.
Do sin(x), square it, and then multiply it by two.
2 sin^2 theta = 1/4 sin^2 theta = 1/8 sin theta = sqrt(1/8) theta = arcsin(sqrt(1/8))
sin cubed + cos cubed (sin + cos)( sin squared - sin.cos + cos squared) (sin + cos)(1 + sin.cos)
You can use the Pythagorean identity to solve this:(sin theta) squared + (cos theta) squared = 1.
22
No, (sinx)^2 + (cosx)^2=1 is though
1
Multiply both sides by sin(1-cos) and you lose the denominators and get (sin squared) minus 1+cos times 1-cos. Then multiply out (i.e. expand) 1+cos times 1-cos, which will of course give the difference of two squares: 1 - (cos squared). (because the cross terms cancel out.) (This is diff of 2 squares because 1 is the square of 1.) And so you get (sin squared) - (1 - (cos squared)) = (sin squared) + (cos squared) - 1. Then from basic trig we know that (sin squared) + (cos squared) = 1, so this is 0.
2 x cosine squared x -1 which also equals cos (2x)