Calculus Examples
∫6(2x-1)-3dx∫6(2x−1)−3dx , u=2x-1u=2x−1
Step 1
Step 1.1
Let u=2x-1u=2x−1. Find dudxdudx.
Step 1.1.1
Differentiate 2x-12x−1.
ddx[2x-1]ddx[2x−1]
Step 1.1.2
By the Sum Rule, the derivative of 2x-12x−1 with respect to xx is ddx[2x]+ddx[-1]ddx[2x]+ddx[−1].
ddx[2x]+ddx[-1]ddx[2x]+ddx[−1]
Step 1.1.3
Evaluate ddx[2x]ddx[2x].
Step 1.1.3.1
Since 22 is constant with respect to xx, the derivative of 2x2x with respect to xx is 2ddx[x]2ddx[x].
2ddx[x]+ddx[-1]2ddx[x]+ddx[−1]
Step 1.1.3.2
Differentiate using the Power Rule which states that ddx[xn]ddx[xn] is nxn-1nxn−1 where n=1n=1.
2⋅1+ddx[-1]2⋅1+ddx[−1]
Step 1.1.3.3
Multiply 22 by 11.
2+ddx[-1]2+ddx[−1]
2+ddx[-1]2+ddx[−1]
Step 1.1.4
Differentiate using the Constant Rule.
Step 1.1.4.1
Since -1−1 is constant with respect to xx, the derivative of -1−1 with respect to x is 0.
2+0
Step 1.1.4.2
Add 2 and 0.
2
2
2
Step 1.2
Rewrite the problem using u and du.
∫3u3du
∫3u3du
Step 2
Since 3 is constant with respect to u, move 3 out of the integral.
3∫1u3du
Step 3
Step 3.1
Move u3 out of the denominator by raising it to the -1 power.
3∫(u3)-1du
Step 3.2
Multiply the exponents in (u3)-1.
Step 3.2.1
Apply the power rule and multiply exponents, (am)n=amn.
3∫u3⋅-1du
Step 3.2.2
Multiply 3 by -1.
3∫u-3du
3∫u-3du
3∫u-3du
Step 4
By the Power Rule, the integral of u-3 with respect to u is -12u-2.
3(-12u-2+C)
Step 5
Step 5.1
Simplify.
Step 5.1.1
Combine u-2 and 12.
3(-u-22+C)
Step 5.1.2
Move u-2 to the denominator using the negative exponent rule b-n=1bn.
3(-12u2+C)
3(-12u2+C)
Step 5.2
Simplify.
3(-12u2)+C
Step 5.3
Simplify.
Step 5.3.1
Multiply -1 by 3.
-312u2+C
Step 5.3.2
Combine -3 and 12u2.
-32u2+C
Step 5.3.3
Move the negative in front of the fraction.
-32u2+C
-32u2+C
-32u2+C
Step 6
Replace all occurrences of u with 2x-1.
-32(2x-1)2+C