PLEASE HELPPP
The function f is giving by
f(x) = (x - 2)(x +4). What are the x-intercepts of the graph representing f?
Answer: Choice B
Range = {-3, 1, 5}
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Explanation:
The domain is the set of all possible input x values. The range is the set of all possible y outputs.
Plug in each x value from the domain, one at a time, to get its corresponding range y value.
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Start with x = -3
f(x) = 2x+3
f(-3) = 2(-3)+3
f(-3) = -6+3
f(-3) = -3
So -3 is in the range.
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Move onto x = -1
f(x) = 2x+3
f(-1) = 2(-1)+3
f(-1) = -2+3
f(-1) = 1
1 is also in the range
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Finally plug in x = 1
f(x) = 2x+3
f(1) = 2(1)+3
f(1) = 2+3
f(1) = 5
The value 5 is the final value in the range.
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All of those values form the set {-3, 1, 5} which is the complete range.
For question number 1:The plot H = H(t) is the parabola and it reaches its maximum in the moment when exactly at midpoint between the roots t = 0 and t = 23. At that moment t = 23/2 or 11.5 seconds.
For question number 2:To find the maximal height, just simply substitute t = 11.5 into the quadratic equation. The answer would be 22.9.
For question number 3:H(t) = 0, or, which is the same as -16t^2 + 368t = 0.Factor the left side to get -16*t*(t - 23) = 0.t = 0, relates to the very start of the process, when the ash started its way up.The other root is t = 23 seconds, and it is precisely the time moment when the bit of ash will go back to the ground.
