Question 40097
{{{ y-k = a(x+3)^2 }}}


OK, put in the values (-5,1)
{{{ y-k = a(x+3)^2 }}}
{{{ 1-k = a(-5+3)^2 }}}
{{{ 1-k = a(-2)^2 }}}
{{{ 1-k = 4a }}}
{{{ 1 = 4a + k }}}
or {{{ 4a + k = 1 }}}


and put in the values (1,7)
{{{ y-k = a(x+3)^2 }}}
{{{ 7-k = a(1+3)^2 }}}
{{{ 7-k = a(4)^2 }}}
{{{ 7-k = 16a }}}
{{{ 7 = 16a + k }}}
or {{{ 16a + k = 7 }}}


So simultaneous equations
 4a + k = 1
16a + k = 7


Subtract these to find a and then find k.


jon.