(0.2,0) is one and I need to find the other using this equation y=5x^2+4x-1?

1 Answer
Jul 29, 2018

Other is #(-1,0)#

Explanation:

It appears that you want to find intercepts formed by the parabola on #x#-axis.

As on #x#-axis, #y=0#, we have

#5x^2+4x-1=0#

or #5x^2+5x-x-1=0#

or #5x(x+1)-1(x+1)=0#

or #(5x-1)(x+1)=0#

Hence either #5x-1=0# i.e. #5x=1# and #x=0.2#

or #x+1=0# i.e. #x=-1#

Hence while one intercept is #(0.2,0)# other intercept is #(-1,0)#

graph{5x^2+4x-1 [-1.286, 1.214, -1.03, 0.22]}