Can you write the function in the form f(x)=mx+b, where m and b are real numbers?
It is not a linear function. See solution.
Practice makes perfect
If the given function is a linear function, it can be written in the slope-intercept form.
f(x)= mx+ b
In this form, m and b are constants. Looking at the given function, we see that something is different.
f(x)=2 x^2-9
The x-term has an exponent. Because of this, the equation cannot be written in the form f(x)=mx+b and therefore is not a linear function.
