00:02
Okay, this tangent then cuts the y -axis at p.
00:07
I want to find the value of p.
00:10
So first step, let's find the line equation of the tangent.
00:14
To do that, i want the slope.
00:16
Well, if i draw a line from here to here, that is a right angle.
00:23
Tangent and radius always meet at a right angle.
00:27
I can work at the slope of this green line.
00:29
So slope of green line is going downhill, so it's minus, and the y value is 16 and the x value 12.
00:44
So that will be, divide by 4, negative 4 thirds.
00:50
Now that implies slope of the red line, the tangent, will be plus 3 quarters.
01:01
It's always negative reciprocal...