#### bugatti79

Hi all,

Can any one confirm that I am not losing it on these 2 problems!?
Solve for x,
$$\displaystyle t=-6x^2+6x$$

I calculate $$\displaystyle x=\frac{-6\pm \sqrt{36-24t}}{-12}$$ which i knw can be further reduced but the answer in the book is $$\displaystyle x=3\pm \sqrt{9-t}$$ and

$$\displaystyle t=\frac{x^2}{2} + \frac{9}{2}-2x$$

I calculate $$\displaystyle x=\frac{4\pm \sqrt{-20+8t}}{2}$$ but the answer in the book is $$\displaystyle x=2 \pm\sqrt{2t-5}$$

thanks

Hi all,

Can any one confirm that I am not losing it on these 2 problems!?

1. Solve for x,

$$\displaystyle t=-6x^2+6x$$

I calculate $$\displaystyle x=\frac{-6\pm \sqrt{36-24t}}{-12}$$ which i know can be further reduced, but the answer in the book is $$\displaystyle x=3\pm \sqrt{9-t}$$

The book solution is the answer to...... $$\displaystyle t=-x^2+6x$$

and 2.

$$\displaystyle t=\frac{x^2}{2} + \frac{9}{2}-2x$$

I calculate $$\displaystyle x=\frac{4\pm \sqrt{-20+8t}}{2}$$ but the answer in the book is $$\displaystyle x=2 \pm\sqrt{2t-5}$$

Just continue to simplify

thanks
$$\displaystyle \frac{4\pm\sqrt{-20+8t}}{2}=\frac{4}{2}\pm\frac{\sqrt{8t-20}}{\sqrt{4}}=2\pm\sqrt{\frac{8t-20}{4}}$$

#### bugatti79

ah, so simple (Doh)
i may start thinking outside the box!!!

thanks archie!