If the slope of the tangent to 4x2+cx+2ey=2 at x=0 is 4, then what is the value of c?

If the slope of the tangent to 4x2+cx+2ey=2 at x=0 is 4, then find c

2 Answers
Apr 3, 2018

The value of c is 8.

Explanation:

First we will solve for the value of y at x=0.

4(0)2+0(x)+2ey=2

2ey=2

ey=1

y=0

We must find the first derivative because this gives us the slope of the tangent at x=a.

8x+c+2ey(dydx)=0

2ey(dydx)=c8x

dydx=c8x2ey

We want to find at what value of c that dydx=4.

4=c8(0)2(1)

8=c

c=8

Hopefully this helps!

Apr 3, 2018

C=8ey

Explanation:

4x2+Cx+2ey=2, differentiating both sides , implicitly gives,

8[0]+C+2eydydx=0, Given that the slope is 4 at x=0 we have,

C+8ey=0, since dydx=4, therefore, C=8ey