## anonymous 5 years ago $f(x)=2(x-2)^{2}-1$ x-intercept Help!!!

1. anonymous

i coulda sworn i did this problem, but lets do it again two ways.

2. anonymous

first way is to expand and get $2(x-2)(x-2)-1=2(x^2-4x+4)-1=2x^2-8x+8-1$ $=2x^2-8x+7$

3. anonymous

now you can use the quadratic formula if you like, or you can complete the square

4. anonymous

x-intercept is where the graph crosses the x-axis. There are two of these, they are called the zero's of x. One is 1.2928932, and the other is: x= 2.707

5. anonymous

do you want to complete the square? it may be easier in this case.

6. anonymous

ok so the x-intercept is 1.3 and 2.7 what would y-intercept be???

7. anonymous

actually the x - intercepts are $\frac{4\pm\sqrt{2}}{2}$