Weird u-substitution for the integral of sqrt(1+x^2)

Evaluate the Integral u sqrt(1- u^2) du using the substitution rule

Integral of sqrt(1+x^2) (substitution + by parts)

Integral of x*sqrt(1-x^2) vs. integral of sqrt(1-x^2), u-substitution vs. integration by parts

100 integrals (world record?)

integral of sqrt(1+x^2), trig substitution, calculus 2 tutorial

(Method 1) Integral of sqrt(1-cos(x)) (substitution + trigonometric identities)

Integral of sqrt(1-x^2) (substitution + trigonometric identities)

integral of sqrt(1+1/x), by u-substitution

Integral of sqrt(x^2+1), integral of sqrt(x^2-1), integral of sqrt(1-x^2)

(Method 2) Integral of sqrt(1-sin(x)) (substitution + trigonometric identities)

integral of sqrt(1-x^2), trig substitution, calculus 2 tutorial

Integral of sqrt(x-1)

Integral of 1/sqrt(1+x^2) (substitution + substitution)

Integral of sqrt(1-x)/(x+sqrt(x)) (substitution + substitution)

(Method 1) Integral of x/sqrt(1-x^2) (substitution)

Integrate 1/sqrt(1-x^2)

integrate 7/sqrt(1 - u^2) du

Square root u-substitution integral x^2*sqrt(x+1), explicit u-substitution with a square root.

Integral of x/sqrt(1-4x^2), How to integration by substitution method, Indefinite integration