Answer:
a
Step-by-step explanation:
Answer:
Cos E= 24/25
Step-by-step explanation:
Length of hypotenuse: 7^2+24^2=625. 625 square root=25
Thus, DE is 25.
Sin D= 24/25, so that is false.
Tan D= 24/7, so that is false.
Cos E= 24/25, so that is true
Sin E= 7/25, so that is false.
Hello !
cos (a+b) = cos a cos b - sin a sin b
sin (a+b) = sin a cos b + sin b cos a
cos (a+b+c) = cos (a+(b+c))
cos (a+b+c) = cos a cos (b+c) - sin a sin (b+c)
cos (a+b+c) = cos a (cos b cos c - sin b sin c) - sin a (sin b cos c + sin c cos b)
cos (a+b+c)=cos a cos b cos c - cos a sin b sin c - sin a sin b cos c - sin a cos b sin c
Every single one of those polynomials factors. When factored, your expression looks like this:

. When you cancel the like factors out, what you're left with is this:

. That means that b = 9, c = 1, and d = -2