SOLUTION: Graph the following function to find the​ x-intercepts. Y=-5x^2+2x+3

Algebra ->  Graphs -> SOLUTION: Graph the following function to find the​ x-intercepts. Y=-5x^2+2x+3      Log On


   

Question 1060424: Graph the following function to find the​ x-intercepts. Y=-5x^2+2x+3
Found 2 solutions by josgarithmetic, MathTherapy:
Answer by josgarithmetic(39621) About Me  (Show Source):
You can put this solution on YOUR website!
Easier to make the graph if you know the vertex and the axis intercepts. Your parabola is concave down (see the coefficient on the leading term negative).

y=-5%28x%5E2-%282%2F5%29x-3%2F5%29

y=-5%28x%5E2-%282%2F5%29x%2B%282%2F20%29%5E2-%282%2F20%29%5E2-3%2F5%29------this step is Completing The Square.

y=-5%28x%5E2-%282%2F5%29x%2B%281%2F10%29%5E2-%281%2F10%29%5E2-3%2F5%29

y=-5%28%28x-1%2F10%29%5E2-1%2F100-60%2F100%29

y=-5%28x-1%2F10%29%5E2%2B61%2F20

The MAXIMUM value, vertex, is at ( 1/10, 61/20 ), and you can solve the equation for the zeros of the graph.

graph%28300%2C300%2C-4%2C4%2C-4%2C4%2C-5x%5E2%2B2x%2B3%29

Answer by MathTherapy(10555) About Me  (Show Source):
You can put this solution on YOUR website!

Graph the following function to find the​ x-intercepts. Y=-5x^2+2x+3
The x-coordinate of the vertex is found at: matrix%281%2C6%2C+x+=+-+b%2F%282a%29%2C++or%2C+at%2C++x%2C+%22=%22%2C+1%2F5%29

Substituting x+=+1%2F5, matrix%281%2C5%2C+%22y-coordinate%22%2C+of%2C+vertex%2C+%22is%3A%22%2C+16%2F5%29



Let no-one tell you otherwise!!