To determine
To find:
Equation of the tangent line
Answer
y=-xπ+1
Explanation
1) Concept:
i) Fundamental Theorem of calculus. If f(x) is continuous on [a, b] and
gx=∫axf(t) dt
then g'x=f(x)
2) Formula:
i) Slope point form:
y-y1=m ·(x-x1)
3) Given:
Fx=∫πxcostt dt
4) Calculation:The slope of tangent to the curve at x is given by derivative at x.
Here
Fx=∫πxcostt dt
By using Fundamental Theorem of Calculus,
F’x= cosxx
Given that, x=π,
Substitute value of x in F’(x)
F’(π)=cosππ
Since, cosπ=-1
F’π=-1π
Therefore, slope of tangent line at x=π is
-1π At x=π
Fx=∫πxcostt dt= ∫ππcosxx dx=0 since upper and lower limits of integral are same.
Therefore, Fπ=0
Use point slope form to find equation of tangent line,
y-y1=m ·(x-x1)
Now, m=-1π and x1=π ,y1=0
Substituting the value,
y-0=-1π ·(x-π)
y=-1π ·(x-π)
Applying distributive property,
y=-xπ+1
This is the equation of tangent line to the curve, y=Fx at the point π,0.
Conclusion:
Therefore, the equation of tangent line is
y=-xπ+1