We know that sin2x=2sinxcosx
(search the net for proof if you wish)
So the original equation becomes
2sinxcosx-sinx=0
The two terms both have sinx that can be taken out to get:
sinx(2cosx-1)=0
This is true if sinx=0 or 2cosx-1=0 , rewritten: cosx=1/2
sinx=0 than x=2kπ
cosx=1/2 than x=π/3+2kπ
where k is an integer
Answer:
1)Take the smallest power common
2) simply the bracket
3) multiply with the power taken common
Example:
5×10⁶ - 4×10³
Smaller power is 3, so take 10³ common:
10³[(5×10²) - 4]
10³[500 - 4]
10³(496)
496×10³
4.96×10⁵
3. -4x - 6
-3(x + 2) - x → ( distribute bracket by - 3)
= - 3x - 6 -x → (collect like terms)
=( - 3x - x) - 6 = - 4x - 6
4. A has the smallest value
A =( 2 - 3 ) = -1
B = 2 × 3 = 6
C = 2 + 3 = 5
D = 
A is negative while the others are all positive.
Thus A is the smallest value expression
