Answer:
k=24
Step-by-step explanation:
The tangent of the function f at x=a, can be found by differentiating f w.r.t. x and then replacing x with a.
f=-x^2+8x+20
Differentiating both sides:
f'=(-x^2+8x+20)'
By sum rule:
f'=(-x^2)'+(8x)'+(20)'
By constant multiple rule:
f'=-(x^2)'+8(x)'+(20)'
By constant rule:
f'=-(x^2)+8(x)'+0
By power rule:
f'=-2x+8
f' at x=a is -2a+8
This is the slope of any tangent line to the curve f.
The slope of g is 4 if you compare it to slope intercept form y=mx+b.
So we gave -2a+8=4.
Subtracr 8 on both sides: -2a=-4
Divide both sides by -2: a=2
The tangent line to the curve at x=2 is y=4x+k.
To tind y we must first know the y-coordinate of the point of tangency.
If x=2, then
f(2)=-(2)^2+8(2)+20=-4+16+20=12+20=32
So the point is (2,32).
g(x)=4x+k and we know g(2)=32.
This gives us:
32=4(2)+k
32=8+k
k=32-8
k=24
Table (A) represents the parabola y = x² - 6x in which the parabola opens and the y-intercept is (0, 0) table (A) is the correct choice.
<h3>What is a parabola?</h3>
It is defined as the graph of a quadratic function that has something bowl-shaped.
We have the tables shown in the picture.
We know the quadratic form of a parabola is:
y = ax² + bx + c
If a > 0 the parabola opens
In the equation:
y = x² - 6x
1 > 0 the parabola opens and y-intercept is:
y = 0 (plug x = 0 in the given equation)
a = 1, b = -6, and c = 0
Thus, table (A) represents the parabola y = x² - 6x in which the parabola opens and the y-intercept is (0, 0) table (A) is the correct choice.
Learn more about the parabola here:
brainly.com/question/8708520
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Answer:
It's too short. Write at least 20 characters to explain it well.