Question

What are the zeros of the function `y=2x^2-3x-20`, and why?

Answer 1

`x_1=4 or x_2=5/2=2.5`

Explanation:

The zeros, or also know as interceptions of the x-axis, can be determinated by `y=0`

`0=2x^2-3x-20|:2`
`0=x^2-3/2x-10`

`0=(x-3/4)^2-9/16-10`
`0=(x-3/4)^2-169/16|+169/16|sqrt()`
`+-13/4=x-3/4|+3/4`
`x=3/4+-13/4`
`x_1=4 or x_2=5/2=2.5`