Answer:
Step-by-step explanation:
![\dfrac 12 \left[\sin(a+b)+\sin(a-b) \right]\\\\\\=\dfrac 12\left[ 2 \sin a \cos b\right]\\\\\\=\sin a \cos b](https://tex.z-dn.net/?f=%5Cdfrac%2012%20%5Cleft%5B%5Csin%28a%2Bb%29%2B%5Csin%28a-b%29%20%5Cright%5D%5C%5C%5C%5C%5C%5C%3D%5Cdfrac%2012%5Cleft%5B%202%20%5Csin%20a%20%5Ccos%20b%5Cright%5D%5C%5C%5C%5C%5C%5C%3D%5Csin%20a%20%5Ccos%20b)
Answer:
4
Step-by-step explanation:
y inversely proportional to x
y=1k/x
4=k/4
k=4×4
k=16
to find y
y=16/4
y=4
Answer:
(0 ; -3)
Step-by-step explanation:
The y-intercept is where the line touches the y axis meaning that x is 0.
(-3x^2 - 5x + 1) + (8x^2 - 2x - 9)
1st remove the parenthesis
-3x^2 - 5x + 1 + 8x^2 - 2x - 9
then combine like terms
5x^2 - 7x - 8 is the final answer
