Answer:
They are at the same height at 1.13 seconds.
Step-by-step explanation:
Remark
The rockets are at the same height when f(x) = g(x) [see below] are the same. So you can equate them.
Givens
f(x) = - 16x^2 + 74x + 9
g(x) = -16x^2 + 82x I have changed this so you don't have 2 f(x)s
Solution
- f(x) = g(x)
- -16x^2 + 74x + 9 = -16x^2 + 82x Add: 16x^2 to both sides
- -16x^2+16x^2+74x + 9 = -16x^2+16x^2 + 82x Combine terms
- 74x + 9 = 82x Subtract 74x from both sides
- 74x - 74x + 9 = 82x - 74x Combine
- 9 = 8x Divide by 8
- 9/8 = 8x/8
- x = 1 1/8 Convert to decimal
- x = 1.125
- x = 1.13 [rounded]
-1(18+4x)=8
Then you distribute
-18-4x=8
-4x=26
X= -6.5
To solve this function, all we need to do is substitute -4.3 in for wherever "x" appears and then simplify.
f(x) = 7.45x + 33.7; x = -4.3
f(-4.3) = 7.45(-4.3) + 33.7
f(-4.3) = -32.035 + 33.7
f(-4.3) = 1.665
This means that, when x = -4.3, f(x) = 1.665.
Note: It may help to remember that, in a function such as this, f(x) can be thought of as the "y" value that corresponds to the given "x" value (in fact, when writing it out with words, f(x) is the same as "function of x"). And, if you are given a value for f(x), then the opposite is true. Just substitute in the value given for f(x) and solve for x.
Hope this helps!
