First slide
Equation of line in Straight lines
Question

The point where the perpendicular from the point 5,7 meets the line 3x+4y+12=0 is h,k then the value of h2k+2 is

Easy
Solution

If h,k is foot of the perpendicular of x1,y1 on the line ax+by+c=0 then  hx1a=ky1b=ax1+by1+ca2+b2

Hence, 

 h+53=k74=35+47+1232+42h+53=k74=2525h+53=k74=1           

Therefore,

h+53=1h+5=3h=2

 And    

k74=1k7=4k=3

Hence,

h2k+2=223+2=28

Therefore,h2k+2=0.25                         

Get Instant Solutions
When in doubt download our app. Now available Google Play Store- Doubts App
Download Now
Doubts App