document.write( "Question 704340: Can someone please help me understand this question? I would like to know the process of how you come to the answers as I have a test tomorrow!
\n" );
document.write( "y=-2(x-3)^2+8
\n" );
document.write( "a)State the coordinates of the vertex
\n" );
document.write( "b)State whether is has a max or min value and what that is?
\n" );
document.write( "c)State the equation of the axis of symmetry
\n" );
document.write( "d)State the y-intercept.
\n" );
document.write( "If you could show me how you reach each answer..that would be amazing!
\n" );
document.write( "Thank you \n" );
document.write( "
Algebra.Com's Answer #434055 by nerdybill(7384)![]() ![]() You can put this solution on YOUR website! y=-2(x-3)^2+8 \n" ); document.write( "a)State the coordinates of the vertex \n" ); document.write( "You have to remember the \"vertex form\" of a quadratic: \n" ); document.write( "y = a(x-h)^2 + k \n" ); document.write( "where (h,k) is the vertex \n" ); document.write( "since your equation was: \n" ); document.write( "y=-2(x-3)^2+8 \n" ); document.write( "we immediately can see that the vertex is at: \n" ); document.write( "(h,k) = (3,8) \n" ); document.write( "b)State whether is has a max or min value and what that is? \n" ); document.write( "We can tell by the \"coefficient\" associated with the x^2 term: \n" ); document.write( "y=-2(x-3)^2+8 \n" ); document.write( "expanding the above: \n" ); document.write( "y=-2(x^2-6x+9)+8 \n" ); document.write( "y=-2x^2+12x-18+8 \n" ); document.write( "y=-2x^2+12x-10 \n" ); document.write( "Since it will be \"negative\" -- we conclude that it will be a parabola that opens downwards. Thus the vertex will be the MAX. \n" ); document.write( "Note: do part c first, then come back to this \n" ); document.write( "c)State the equation of the axis of symmetry \n" ); document.write( "axis of symmetry is at: \n" ); document.write( "x = -b/(2a) \n" ); document.write( "x = -12/(2(-2)) \n" ); document.write( "x = -12/(-4) \n" ); document.write( "x = 3 (axis of symmetry) \n" ); document.write( "d)State the y-intercept. \n" ); document.write( "set x to zero: \n" ); document.write( "y=-2x^2+12x-10 \n" ); document.write( "y=-2(0)^2+12(0)-10 \n" ); document.write( "y=0+0-10 \n" ); document.write( "y = -10 \n" ); document.write( "y-intercept is at (0, -10) \n" ); document.write( " \n" ); document.write( " |