Make t the subject of formula S = ut + (frac{1}{2} at^2)

A.
(frac{1}{a}) (u + (sqrt{U^2 – 2as})) 
B.
(frac{1}{a}) {u (pm) (U^{2} – 2as)} 
C.
(frac{1}{a}) {u (pm) (sqrt{2as})} 
D.
(frac{1}{a}) {u + (sqrt{( 2as)})}
Correct Answer: Option A
Explanation
Given S = ut + (frac{1}{2} at^2)
S = ut + (frac{1}{2} at^2)
∴ 2S = 2ut + at^{2}
= at^{2} + 2ut – 2s = 0
t = (frac{2u pm 4u^2 + 2as}{2a})
= 2u (pi) (frac{sqrt{u^2 4u^2 + 2as}}{2a})
= (frac{1}{a}) (u + (sqrt{U^2 – 2as}))