If f(x) = -8x – 6 and g(x) = x+8, what is (fºg)(-7)? Enter the correct answer.

Mathematics

1 answer:

Semmy [17]3 years ago

6 0

9514 1404 393

Answer:

-14

Step-by-step explanation:

$(f\circ g)(x)=f(g(x))=f(x+8)=-8(x+8)-6\\\\(f\circ g)(x)=-8x-70\\\\(f\circ g)(-7)=-8(-7)-70=\boxed{-14}$

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(a)In the attachment

(b)The road of length 35.79 km should be built such that it joins the highway at 19.52km from the perpendicular point P.

Step-by-step explanation:

(a)In the attachment

(b)The distance that enables the driver to reach the city in the shortest time is denoted by the Straight Line RM (from the Ranch to Point M)

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Using Pythagoras theorem

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Time taken on the road $=\frac{\sqrt{30^2+x^2}}{60}$

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Minimum time taken occurs when the derivative of T equals 0.

$T^{'}=\frac{x}{60\sqrt{30^2+x^2}}-\frac{1}{110}\\\frac{x}{60\sqrt{30^2+x^2}}-\frac{1}{110}=0\\\frac{x}{60\sqrt{30^2+x^2}}=\frac{1}{110}\\110x=60\sqrt{30^2+x^2}\\$

Square both sides

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