Here's a question from my Calc HW andI believe my approach is flawed...(adsbygoogle = window.adsbygoogle || []).push({});

Two functions

f(x) = x^2

g(x) = -x^2 + 6x -5

Find the two lines tangent to both functions

I thought I could find the slope where f' and g' are equal so I did:

f'(x) = 2x

g'(x) = -2x + 6

2x = -2x +6

x = 1.5

slope = 2(1.5) = 3

BUT that slope doesn't work as this simply finds an x on the two graphs where the two graphs have the same slope.

Help me please!

THE given answers are

y=2x-1

y=4x-4

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# Homework Help: Tangent to both functions

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