The equation of the curve is given by #y=x^2+ax+3#, where #a# is a constant. Given that this equation can also be written as #y=(x+4)^2+b#, find (1) the value of #a# and of #b# (2) the coordinates of the turning point of the curve Someone can help?

The equation of the curve is given by #y=x^2+ax+3#, where #a# is a constant. Given that this equation can also be written as #y=(x+4)^2+b#, find

(1) the value of #a# and of #b#
(2) the coordinates of the turning point of the curve

2 Answers

The explanation is in the images.

Explanation:


Dec 1, 2017

#a=8,b=-13,(-4,-13)#

Explanation:

#x^2+ax+3to(1)#

#y=(x+4)^2+bto(2)#

#"expanding "(2)" using FOIL"#

#y=x^2+8x+16+b#

#color(blue)"comparing coefficients of like terms"#

#ax-=8xrArra=8#

#16+b-=3rArrb=3-16=-13#

#"the equation of a parabola in "color(blue)"vertex form"# is.

#color(red)(bar(ul(|color(white)(2/2)color(black)(y=a(x-h)^2+k)color(white)(2/2)|)))#

#"where "(h,k)" are the coordinates of the vertex and a"#
#"is a multiplier"#

#y=(x+4)^2-13color(blue)" is in vertex form"#

#rArrcolor(magenta)"vertex "=(-4,-13)larrcolor(blue)"turning point"#