Q11 (i) If y = √x + √ x + √ x +....∞ prove that (2y - 1)

dy / dx

= 1
(ii) If y = √sinx + √ sinx + √ sinx +....∞ prove that (2y - 1)

dy / dx

= cosx
(iii) If y = √tanx + √ tanx + √ tanx +....∞ prove that (2y - 1)

dy / dx

= sec²x

Solution

,,,