Solve (2a^{2}+b)^{2}-2(-2a^{2})^2-b(1/2b)^2+(2a^2-b)^2

$$( 2 a ^ { 2 } + b ) ^ { 2 } - 2 ( - 2 a ^ { 2 } ) ^ { 2 } - b ( \frac { 1 } { 2 } b ) ^ { 2 } + ( 2 a ^ { 2 } - b ) ^ { 2 }$$

Evaluate

$$-\frac{b^{3}}{4}+2b^{2}$$

Solution Steps

Use binomial theorem \left(p+q\right)^{2}=p^{2}+2pq+q^{2} to expand \left(2a^{2}+b\right)^{2}.

$$4\left(a^{2}\right)^{2}+4a^{2}b+b^{2}-2\left(-2a^{2}\right)^{2}-b\times \left(\frac{1}{2}b\right)^{2}+\left(2a^{2}-b\right)^{2}$$

To raise a power to another power, multiply the exponents. Multiply 2 and 2 to get 4.

$$4a^{4}+4a^{2}b+b^{2}-2\left(-2a^{2}\right)^{2}-b\times \left(\frac{1}{2}b\right)^{2}+\left(2a^{2}-b\right)^{2}$$

Expand \left(-2a^{2}\right)^{2}.

$$4a^{4}+4a^{2}b+b^{2}-2\left(-2\right)^{2}\left(a^{2}\right)^{2}-b\times \left(\frac{1}{2}b\right)^{2}+\left(2a^{2}-b\right)^{2}$$

To raise a power to another power, multiply the exponents. Multiply 2 and 2 to get 4.

$$4a^{4}+4a^{2}b+b^{2}-2\left(-2\right)^{2}a^{4}-b\times \left(\frac{1}{2}b\right)^{2}+\left(2a^{2}-b\right)^{2}$$

Calculate -2 to the power of 2 and get 4.

$$4a^{4}+4a^{2}b+b^{2}-2\times 4a^{4}-b\times \left(\frac{1}{2}b\right)^{2}+\left(2a^{2}-b\right)^{2}$$

Multiply 2 and 4 to get 8.

$$4a^{4}+4a^{2}b+b^{2}-8a^{4}-b\times \left(\frac{1}{2}b\right)^{2}+\left(2a^{2}-b\right)^{2}$$

Combine 4a^{4} and -8a^{4} to get -4a^{4}.

$$-4a^{4}+4a^{2}b+b^{2}-b\times \left(\frac{1}{2}b\right)^{2}+\left(2a^{2}-b\right)^{2}$$

Expand \left(\frac{1}{2}b\right)^{2}.

$$-4a^{4}+4a^{2}b+b^{2}-b\times \left(\frac{1}{2}\right)^{2}b^{2}+\left(2a^{2}-b\right)^{2}$$

Calculate \frac{1}{2} to the power of 2 and get \frac{1}{4}.

$$-4a^{4}+4a^{2}b+b^{2}-b\times \frac{1}{4}b^{2}+\left(2a^{2}-b\right)^{2}$$

To multiply powers of the same base, add their exponents. Add 1 and 2 to get 3.

$$-4a^{4}+4a^{2}b+b^{2}-b^{3}\times \frac{1}{4}+\left(2a^{2}-b\right)^{2}$$

Use binomial theorem \left(p-q\right)^{2}=p^{2}-2pq+q^{2} to expand \left(2a^{2}-b\right)^{2}.

$$-4a^{4}+4a^{2}b+b^{2}-b^{3}\times \frac{1}{4}+4\left(a^{2}\right)^{2}-4a^{2}b+b^{2}$$

To raise a power to another power, multiply the exponents. Multiply 2 and 2 to get 4.

$$-4a^{4}+4a^{2}b+b^{2}-b^{3}\times \frac{1}{4}+4a^{4}-4a^{2}b+b^{2}$$

Multiply -1 and \frac{1}{4} to get -\frac{1}{4}.

$$-4a^{4}+4a^{2}b+b^{2}-\frac{1}{4}b^{3}+4a^{4}-4a^{2}b+b^{2}$$

Combine -4a^{4} and 4a^{4} to get 0.

$$4a^{2}b+b^{2}-\frac{1}{4}b^{3}-4a^{2}b+b^{2}$$

Combine 4a^{2}b and -4a^{2}b to get 0.

$$b^{2}-\frac{1}{4}b^{3}+b^{2}$$

Combine b^{2} and b^{2} to get 2b^{2}.

$$2b^{2}-\frac{1}{4}b^{3}$$

Expand

$$-\frac{b^{3}}{4}+2b^{2}$$

Solution Steps

Use binomial theorem \left(p+q\right)^{2}=p^{2}+2pq+q^{2} to expand \left(2a^{2}+b\right)^{2}.

$$4\left(a^{2}\right)^{2}+4a^{2}b+b^{2}-2\left(-2a^{2}\right)^{2}-b\times \left(\frac{1}{2}b\right)^{2}+\left(2a^{2}-b\right)^{2}$$

To raise a power to another power, multiply the exponents. Multiply 2 and 2 to get 4.

$$4a^{4}+4a^{2}b+b^{2}-2\left(-2a^{2}\right)^{2}-b\times \left(\frac{1}{2}b\right)^{2}+\left(2a^{2}-b\right)^{2}$$

Expand \left(-2a^{2}\right)^{2}.

$$4a^{4}+4a^{2}b+b^{2}-2\left(-2\right)^{2}\left(a^{2}\right)^{2}-b\times \left(\frac{1}{2}b\right)^{2}+\left(2a^{2}-b\right)^{2}$$

To raise a power to another power, multiply the exponents. Multiply 2 and 2 to get 4.

$$4a^{4}+4a^{2}b+b^{2}-2\left(-2\right)^{2}a^{4}-b\times \left(\frac{1}{2}b\right)^{2}+\left(2a^{2}-b\right)^{2}$$

Calculate -2 to the power of 2 and get 4.

$$4a^{4}+4a^{2}b+b^{2}-2\times 4a^{4}-b\times \left(\frac{1}{2}b\right)^{2}+\left(2a^{2}-b\right)^{2}$$

Multiply 2 and 4 to get 8.

$$4a^{4}+4a^{2}b+b^{2}-8a^{4}-b\times \left(\frac{1}{2}b\right)^{2}+\left(2a^{2}-b\right)^{2}$$

Combine 4a^{4} and -8a^{4} to get -4a^{4}.

$$-4a^{4}+4a^{2}b+b^{2}-b\times \left(\frac{1}{2}b\right)^{2}+\left(2a^{2}-b\right)^{2}$$

Expand \left(\frac{1}{2}b\right)^{2}.

$$-4a^{4}+4a^{2}b+b^{2}-b\times \left(\frac{1}{2}\right)^{2}b^{2}+\left(2a^{2}-b\right)^{2}$$

Calculate \frac{1}{2} to the power of 2 and get \frac{1}{4}.

$$-4a^{4}+4a^{2}b+b^{2}-b\times \frac{1}{4}b^{2}+\left(2a^{2}-b\right)^{2}$$

To multiply powers of the same base, add their exponents. Add 1 and 2 to get 3.

$$-4a^{4}+4a^{2}b+b^{2}-b^{3}\times \frac{1}{4}+\left(2a^{2}-b\right)^{2}$$

Use binomial theorem \left(p-q\right)^{2}=p^{2}-2pq+q^{2} to expand \left(2a^{2}-b\right)^{2}.

$$-4a^{4}+4a^{2}b+b^{2}-b^{3}\times \frac{1}{4}+4\left(a^{2}\right)^{2}-4a^{2}b+b^{2}$$

To raise a power to another power, multiply the exponents. Multiply 2 and 2 to get 4.

$$-4a^{4}+4a^{2}b+b^{2}-b^{3}\times \frac{1}{4}+4a^{4}-4a^{2}b+b^{2}$$

Multiply -1 and \frac{1}{4} to get -\frac{1}{4}.

$$-4a^{4}+4a^{2}b+b^{2}-\frac{1}{4}b^{3}+4a^{4}-4a^{2}b+b^{2}$$

Combine -4a^{4} and 4a^{4} to get 0.

$$4a^{2}b+b^{2}-\frac{1}{4}b^{3}-4a^{2}b+b^{2}$$

Combine 4a^{2}b and -4a^{2}b to get 0.

$$b^{2}-\frac{1}{4}b^{3}+b^{2}$$

Combine b^{2} and b^{2} to get 2b^{2}.

$$2b^{2}-\frac{1}{4}b^{3}$$