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.
Answer:
Step-by-step explanation:
If Elena walk 12 miles, and then 0.25 that distance
0.25=1/4
12*1/4=3 miles is 1/4 of the distance
she walked in total 12+3=15 miles
choice A =12+12*1/4
Answer:
0
Step-by-step explanation:
3x - 9 if x = 3
Substitute:
3(3) - 9 =
9 - 9 = 0
This can be written as a function: f(x) = 3x - 9
f(3) = 3x - 9
f(3) = 3(3) - 9
f(3) = 9 - 9
f(3) = 0
-Chetan K
2x+10 is the correct answer.