1 Answers
Shaswata Roy
·2013-04-06 02:49:33
(i)t(x)=\frac{\sqrt{9^{2}+x^{2}}}{4}+\frac{15-x}{5}
(ii)\frac{\mathrm{d}t(x)}{\mathrm{d}x}=\frac{x}{4\sqrt{9^{2}+x^{2}}}-\frac{1}{5}
t is minimum when dtdx=0 and d t2d2 x>0
Therefore x = 12km
- Akash Anand Excellent work Upvote·0· Reply ·2013-04-06 03:16:46