How do you find the arc length of the curve y=(5sqrt7)/3x^(3/2)-9y=5√73x32−9 over the interval [0,5]?
1 Answer
Explanation:
The arc length of a function
s=int_a^bsqrt(1+(dy/dx)^2)color(white).dxs=∫ba√1+(dydx)2.dx
Here:
y=(5sqrt7)/3x^(3/2)-9y=5√73x32−9
dy/dx=(5sqrt7)/3(3/2x^(1/2))=(5sqrt7)/2x^(1/2)dydx=5√73(32x12)=5√72x12
Then the arc length desired is:
s=int_0^5sqrt(1+((5sqrt7)/2x^(1/2))^2)color(white).dxs=∫50 ⎷1+(5√72x12)2.dx
s=int_0^5sqrt(1+175/4x)color(white).dxs=∫50√1+1754x.dx
Let
s=4/175int_1^(879//4)u^(1/2)color(white).dus=4175∫879/41u12.du
Integrating using the power rule for integration:
s=4/175(2/3u^(3/2))|_1^(879//4)s=4175(23u32)∣∣∣879/41
s=8/525((879/4)^(3/2)-1^(3/2))s=8525((8794)32−132)
s=8/525(879^(3/2)/8-1)s=8525(879328−1)
s=1/525(879^(3/2)-8)s=1525(87932−8)