SOLUTION: Find the slope and the equation of the tangent line to the graph of the function at the given value of x. f(x)=x^4-17x^2+16; x=1 PLEASE SOLVE A & B from the question above.

Algebra ->  Customizable Word Problem Solvers  -> Geometry -> SOLUTION: Find the slope and the equation of the tangent line to the graph of the function at the given value of x. f(x)=x^4-17x^2+16; x=1 PLEASE SOLVE A & B from the question above.       Log On

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Question 1191024: Find the slope and the equation of the tangent line to the graph of the function at the given value of x.
f(x)=x^4-17x^2+16; x=1
PLEASE SOLVE A & B from the question above.
A) The slope of the tangent line is
B) The equation of the tangent line is y=
  

Found 2 solutions by MathLover1, greenestamps:
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!
f%28x%29=x%5E4-17x%5E2%2B16; x=1
Find the first derivative and evaluate at x=1 to find a slope of the tangent line.
.
f'%28x%29=4x%5E3-34x

f'%28x%29=4%2A1%5E3-34%2A1=-30

Now that we have a slope for the tangent line, we need to identify a point on the line.
We know the tangent line touches the function f%28x%29 at the point x=1, so let's find the value of f%28x%29 at this point:

f%281%29=1%5E4-17%2A1%5E2%2B16=0

So we know the tangent line goes through the point(1,0)

Finally, we can use the point-slope formula for a line to find the equation of the tangent line.
y=mx%2Bb
To find the value of b, substitute the values we have calculated for the point and slope of the tangent line:
0=-30%2A1%2Bb
b=30

the equation of the tangent line is:
y=-30x%2B30





Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


At x=1, we have f(1)=1-17+16=0, so the point of tangency is (1,0)

To find the slope at (1,0), evaluate the derivative of the function at x=1.

f'(x)=4x^3-34x
f'(1)=4-34=-30

The slope at x=1 is -30.

Plug (x,y)=(1,0) and slope m=-30 into either the point-slope or slope-intercept form of the equation of a line to find the equation of the tangent is y=-30x+30.

A graph with x on (-2,2) and y on (-20,20):

graph%28400%2C400%2C-2%2C2%2C-20%2C20%2Cx%5E4-17x%5E2%2B16%2C-30x%2B30%29