find two possible values of p if the lines px-y+1=0 and 3x+y+1=0 intersect at 45 degrees
I am rusty but I will give it a go.
find two possible values of p if the lines px-y+1=0 and 3x+y+1=0 intersect at 45 degrees
px-y+1=0 y=px+1 gradient =p
this line makes an angle of atan(p) with the positive axis I'll call this θ1
3x+y+1=0 y=-3x-1 gradient = -3
this line makes an angle of atan(-3) with the positive axis I'll call this θ2
Now we want
θ1−θ2=±π4
You need to use the last formula, do you think you can try to take it from here :)