SOLUTION: Complete the general form equation of the parabola that passes through (3,−73)with vertex at (−2,2)Enter the quadratic expression in general form, ax^2+bx+c.

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: Complete the general form equation of the parabola that passes through (3,−73)with vertex at (−2,2)Enter the quadratic expression in general form, ax^2+bx+c.      Log On


   



Question 1126205: Complete the general form equation of the parabola that passes through (3,−73)with vertex at (−2,2)Enter the quadratic expression in general form, ax^2+bx+c.
Found 2 solutions by josgarithmetic, josmiceli:
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
Same idea as already shown, just with different values.
https://www.algebra.com/algebra/homework/Quadratic-relations-and-conic-sections/Quadratic-relations-and-conic-sections.faq.question.1126203.html
https://www.algebra.com/algebra/homework/Quadratic-relations-and-conic-sections/Quadratic-relations-and-conic-sections.faq.question.1126203.html

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
( 3, -73 )
+y+=+a%2Ax%5E2+%2B+b%2Ax+%2B+c+
+-73+=+a%2A3%5E2+%2B+b%2A3+%2B+c+
(1) +9a+%2B+3b+=+-c+-+73+
------------------------------
(-2, 2 )
+2+=+a%2A%28-2%29%5E2+%2B+b%2A%28-2%29+%2B+c+
(2) +4a+-+2b+=+-c+%2B+2+
--------------------------------
(-2,2 )
The x-value of vertex is at:
+x%5Bv%5D+=+-b%2F%282a%29+
+-2+=+-b%2F%282a%29+
+-b+=+-4a+
+b+=+4a+
Plug this back into (1) and (2)
(1) +9a+%2B+3%2A%284a%29+=+-c+-+73+
(1) +9a+%2B+12a+=+-c+-+73+
(1) +21a+%2B+c+=+-+73+
and
(2) +4a+-+2%2A%284a%29+=+-c+%2B+2+
(2) +4a+-+8a+%2B+c+=+2+
(2) +-4a+%2B+c+=+2+
----------------------------------
subtract (2) from (1)
+25a+=+-75+
+a+=+-3+
and
+b+=+4a+
+b+=+-12+
and
(2) +-4%2A%28-3%29+%2B+c+=+2+
(2) +12+%2B+c+=+2+
(2) +c+=+-10+
------------------------------
the equation is:
+y+=+-3x%5E2+-+12x+-+10+
------------------------------
check:
( 3, -73 )
+-73+=+-3%2A3%5E2+-+12%2A3+-+10+
+-73+=+-27+-+36+-+10+
+-73+=+-73+
and
( -2,2 )
+2+=+-3%2A%28-2%29%5E2+-+12%2A%28-2%29+-+10+
+2+=+-3%2A4+%2B+24+-+10+
+2+=+-12+%2B+24+-+10+
+2+=+2+
OK