from a handpicked tutor in LIVE 1-to-1 classes
The length of the curve y = x4 from x = 1 to x = 5 is given by?
We will be using the arc length formula to get the exact length of the curve and solve this.
Answer: The length of the curve y = x4 from x = 1 to x = 5 is ln|500 + 53√89| - ln|4 + √17|.
Let's solve this step by step.
Explanation:
Given, y = x4 , x = 1 to x = 5
Length of the curve y = f(x) from x = a to x = b is given by: \(\int_{a}^{b}\) √1 + [f′(x)]2 dx
Let's find the first derivative of y = x4.
y = x4
dy/dx = 4x3
Length of curve =\(\int_{1}^{5}\) √[1 + {f′(x)}]2 dx
=\(\int_{1}^{5}\) √[1 + (4x3)2] dx
= \(\int_{1}^{5}\) √[1 + 16x6] dx
Substitue 4x3 = tanθ in the indefinite integral ∫ √[1 + 16x6] dx:
= ∫ √[1 + tan2θ] dx
= ∫ √sec2θ dx
= ∫ secθ dx
= ln|tanθ + secθ|
Resubstitute the values: tanθ = 4x3, and secθ = √[1 + 16x6]
= [ln|4x3 + √1 + 16x6 |]\(^5_1\)
= [ln|4(5)3 + √{1 + 16(5)6}|] - [ln|4(1)3 + √{1 + 16(1)6}|]
= [ln|4(125) + √{1 + 16(15625)}|] - [ln|4 + √{1 + 16}|]
= [ln|500 + √250001|] - [ln|4 + √17|]
= ln|500 + 53√89| - ln|4 + √17|
Hence, the length of the curve y = x4 from x = 1 to x = 5 is ln|500 + 53√89| - ln|4 + √17|.
visual curriculum