Question

If (a,a + square root 3) lies on the graph of y=2x, then a = ?

Answer 1

Start with y = 2x. Subst. a for x and a+sqrt(3) for y:

a+sqrt(3) = 2a

Subtracting a from both sides: sqrt(3) = a

Answer 2

If the point

`(a \: \: a √(3) )`
lies on

`y = 2x`
then it must satisfy it.

That is


`a + √(3) = 2(a)`

`\rightarrow \: a + √(3) = 2a`


Grouping like terms we have,


`√(3) = 2a - a`

`\therefore \: a = √(3)`