cos(a - b) - cos(a + b) = 2sin(a)sin(b)
[cos(a)cos(b) + sin(a)sin(b)] - [cos(a)cos(b) - sin(a)sin(b)] = 2sin(a)sin(b)
[cos(a)cos(b) - cos(a)cos(b)] + [sin(a)sin(b) + sin(a)sin(b)] = 2sin(a)sin(b)
2sin(a)sin(b) = 2sin(a)sin(b)
Answer:
=4x^2−12x+9
Step-by-step explanation:
=(2x+−3)(2x+−3)
=(2x)(2x)+(2x)(−3)+(−3)(2x)+(−3)(−3)
=4x2−6x−6x+9
=4x2−12x+9
Answer: I can barley see -_-
Step-by-step explanation:
Problem 7
Time is always an independent variable because time marches on doing its own thing without depending on external forces, or other people/things. Instead, other variables depend on time. In this case, the distance d depends on the independent variable t for time.
If the time goes up by 1 hour, then the distance variable goes up by 3 miles. In short, that tells us his speed is 3 mph.
Answer: Choice A) independent = time; dependent = distance
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Problem 8
Everywhere you see an x, replace it with 9. Then use PEMDAS to simplify
f(x) = 5x - 9
f(9) = 5(9) - 9 ... x replaced with 9
f(9) = 45 - 9
f(9) = 36
Answer: 36
