00:01
In this question we're given the function f to be 3x squared minus 7x plus 4.
00:07
We want to find the coordinate on this graph where the tangent is parallel to the line 4x plus y equals to 3.
00:19
So tangent parallel to this line means the gradient of tangent will be the same as the gradient of this line.
00:40
So the line is 4x plus y equals to 3.
00:44
I'm going to bring the 4x to the right side will be minus 4x plus 3.
00:49
Now the general line equation is for y equals to mx plus c, m is the gradient, c is the y -intercept.
01:01
So in this case the gradient of line will be minus 4.
01:11
Tangent gradient will be equals to the line gradient which is minus 4.
01:23
Now the tangent gradient is also same as the differentiation of the curve at that point, at whichever point that we we want.
01:48
For instance x equals to a.
01:50
So therefore let's find our f prime x.
01:56
Now fx is 3x squared minus 7x plus 4...