# What is the equation of the line perpendicular to #y=-7/8x # that passes through # (-5,1) #?

##### 1 Answer

Looks a lot in the explanation. This is because I have explained in a lot of detail what is happening. Standard calculations would not do that!

#### Explanation:

The standared equation of a straight line graph is:

Where

Any slope that is perpendicular to this line has the gradient of:

~~~~~~~~~~~~~~ Comment ~~~~~~~~~~~~~~~~~~~~~~~

I have done it this way to help with signs. Suppose that

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Given:

Let the gradient of the line perpendicular be

So the equation of the perpendicular line is:

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This new line passes through

So

Substitute these into (2) giving:

Add

But

So

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So

Becomes: