Any help? :( y=5x^2-3x-8

[kantev]

Prove that the function y=5x^2-3x-8 has zeros within the interval [0,3] . I would be very thankful if someone can provide the solution

 

[Dr.Peterson]

Prove that the function y=5x^2-3x-8 has zeros within the interval [0,3] . I would be very thankful if someone can provide the solution

I imagine this question was most likely asked after you have been taught the intermediate value theorem. If so, be sure to read what your textbook says about it!

The question then means "prove that the function has at least one zero in the interval", which is what the theorem says. Part of the proof will be to find f(0) and f(3). Do that, and think about the implication.

 

[JeffM]

Prove that the function y=5x^2-3x-8 has zeros within the interval [0,3] . I would be very thankful if someone can provide the solution

This may be a problem that you are overthinking.

All you need to do is find the zeroes of a quadratic function and show that at least one of them is in the specified interval.

Do you know how to find the zeroes of a quadratic?