The Purplemath Forums

by **think** on Mon Mar 23, 2009 12:28 am

Solve 5x^2=10
find the x-intercepts of f(x)=5x^2-10?

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by **stapel_eliz** on Mon Mar 23, 2009 3:24 pm

think wrote:Solve 5x^2=10

Divide through by the 5. Then take the square root of either side, and simplify.

think wrote:find the x-intercepts of f(x)=5x^2-10?

Plug "zero" in for "y" (that is, for f(x)), and solve the resulting quadratic equation.

Note: I think the "point" of this exercise is that you notice the connection between the zeroes of a function f(x) and the solution of the related equation f(x) = 0, since "f(x) = 5x² - 10 = 0" means the same thing as "5x² = 10". :wink:

The Purplemath Forums

Solve 5x^2=10; Find x-intercepts of f(x) = 5x^2 - 10

Solve 5x^2=10; Find x-intercepts of f(x) = 5x^2 - 10