2cosx=2sin2x. Sin2x is an identity for 2sinxcos. So 2[2sinxcosx] gives you 4sinxcosx. 2cosx=4sinxcosx. Divide 2cosx on both sides and gives you 2sinx=0 and divide again, sinx=0. Sinx is 0 at 0 and 360 degrees, or pi and 2pi. So thats what x would be. 0,360,pi,2pi.
Foil method:
FOIL stands for
first-multiply the first term in each set of parenthesis
outer-multiply the outer term in each of the perenthesis
inner- multiply the inner term in each of the parenthesis
last- multiply the last term in each of the parenthesis
(3x+8)(x+1)
(3x*x)=3x^2
(3x*1)=3x
8*x=8x
8*1=8
thus we shall have:
3x^2+3x+8x+8
=3x^2+11x+8
Distributive property:
(3x+8)(x+1)
3x(x+1)+8(x+1)
3x^2+3x+8x+8
=3x^2+11x+8
Both methods are efficient, it all depends with the users preference
Answer:
His son did.
Step-by-step explanation:
His son: 1/4 = 25%
Mr. Strand: 2/5 = 20%
They also need 55% more to wash or in other words 11/20.
Answer:
y=4
Step-by-step explanation:
