document.write( "Question 389589: Find the X-intercept of the parabola with vertex (-1,-108) and y-intercept of (0,-105). \n" ); document.write( "

Algebra.Com's Answer #276096 by ewatrrr(24785) $\"\"$ $\"About$

You can put this solution on YOUR website!


\n" );
document.write( "Hi,  
\n" );
document.write( "the vertex form of a parabola,  where(h,k) is the vertex
\n" );
document.write( "vertex (-1,-108)
\n" );
document.write( "y =a(x+1)^2 -108
\n" );
document.write( "using y-intercept pt(0,-105) to find a
\n" );
document.write( "-105 = a(1)^2 -108
\n" );
document.write( "3 = a
\n" );
document.write( "y = 3(x+1)^2 -108  
\n" );
document.write( "finding x-intercepts when y = 0
\n" );
document.write( "0 = 3(x+1)^2 -108 
\n" );
document.write( "108 = 3(x+1)^2
\n" );
document.write( " 36 = (x+1)^2
\n" );
document.write( "  6 = (x+1)  x = 5
\n" );
document.write( " -6 = (x+1)  x -7
\n" );
document.write( " x-intercepts are Pt(5,0) and Pt(-7,0) \n" );
document.write( "

\n" );