Question

how does 2cosx(4sinx) become
4sin(2x)

Answer 1

2*cos(x)*4*sin(x)


2*cos(x)*2*2*sin(x)


2*2*2*cos(x)*sin(x)


4*2*cos(x)*sin(x)


4*( 2*cos(x)*sin(x) )


4*( sin(2x) )


4*sin(2x)


Note: In step 6, I used the identity 2*sin(x)*cos(x) = sin(2x)

Answer 2

so pulling out the 2^2 in front legal

Answer 3

yes I'm using the commutative property of multiplication

ie

A*B = B*A

Answer 4

b/c i though about factoring but that wouldn't give me 4sin(2x)

Answer 5

not sure how you'd factor

Answer 6

well i jus took out the 2(cosx2sinx)

Answer 7

then jus did the angle ident

Answer 8

but i would jus get 2Sin(2x) so i kn am wrong

Answer 9

is like i lost a power of 2 somewhere