3 sin ( 2 x ) = 3 cos x
3 · 2 sin x cos x - 3 cos x = 0
6 sin x cos x - 3 cos x = 0 /: 3
2 sin x cos x - cos x = 0
cos x ( 2 sin x - 1 )
cos x = 0,
x 1 = π/2, x 2 = 3π/2;
2 sin x - 1 = 0
2 sin x = 1
sin x = 1/2
x 3 = π/6, x 4 = 5π/6.
A+b+c=408
a=a
b=7+a
c=5+a
a+(7+a)+(5+a)=408
3a+12=408
3a=396
a=132
Abel has $132
Belle has $139
Cindy has $137
Prove:
132+139+137=408
Answer: D. (I, II, and III)
Step-by-step explanation:
having a ticket doesn't necessarily mean you will win the lottery, but you must have a ticket to win
not all numbers divisible by 3 are divisible by 6, but all numbers divisible by 6 are also by 3 (since 3 goes into 6 twice)
if a quadrilateral is a square, it is also a rhombus
