Answer
$y=4x-7$
Work Step by Step
Lets assume that equation of line that if tangent to this function is:
$y=ax+b$
İf it is tangent to function then
$f'\left( x\right) =\left( x^{2}-3\right) '=2\times x^{2-1}-0=2x\Rightarrow $
$f'\left( 2\right) =2\times 2=4=a$
$y=ax+b\Rightarrow 1=4\times 2+b\Rightarrow b=-7$
Then equation will be:
$y=4x-7$
