How to find the coordinates?

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2 Answers
Feb 25, 2018

#(x, y)=(4/9, 2)#

Explanation:

#4y=9x+4#
#y^2=9x#
All we need to do is to solve the system of equations, the solutions are the required points, so:
#9x=4y-4#
#x=(4y-4)/9#
#y^2=9*(4y-4)/9#
#y^2-4y+4=0#
#(y-2)^2=0#
#y=2#
#x=4/9#
thus the required coordinated are:
#(x, y)=(4/9, 2)#

Feb 25, 2018

#(x,y)to(4/9,2)#

Explanation:

#4y=9x+4to(1)#

#y^2=9xto(2)#

#"from equation "(1)color(white)(x)9x=4y-4to(3)#

#"substitute "9x=4y-4" in equation "(2)#

#y^2=4y-4larrcolor(blue)"rearrange and equate to zero"#

#rArry^2-4y+4=0#

#rArr(y-2)^2=0rArry=2#

#"substitute "y=2" in equation "(3)#

#9x=8-4rArrx=4/9#

#"point of contact "=(4/9,2)#
graph{(y-9/4x-1)(y^2-9x)=0 [-10, 10, -5, 5]}