# Integral, an algebra problem actually

1. Jul 22, 2005

### mattmns

This one has me baffled.

$$\frac{4}{3}\int_{0}^{1} x^8 \sqrt{1 + 4x^2 + 4x^4}dx$$

Any ideas would be great, I am thinking maybe a trig substitution, but I have yet to figure out how to simplify this thing first. Thanks.

2. Jul 22, 2005

### George Jones

Staff Emeritus
The stuff under the square root forms a perfect square.

Regards,
George

3. Jul 22, 2005

### mattmns

Pff, duhhh! $$(x^2 + \frac{1}{2})^2$$

Thanks!

4. Jul 23, 2005

### sniffer

i did this type of problem before but a multiple choice questions, and there is no matched answer.

later i discovered they used the negative solution, since square root gives positive and negative. so be careful.