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Solve the differential equation dydxdydx+1 = ex + y. - Mathematics

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Question

Solve the differential equation `"dy"/"dx" + 1` = ex + y.

Sum

Solution

Given that: `"dy"/"dx" + 1` = ex + y 

Put x + y = t

∴ `1 + "dy"/"dx" = "dt"/"dx"`

∴ `"dt"/"dx"` = et

⇒ `"dt"/"e"^"t"` = dx

⇒ `"e"^-"t" "dt"` = dx

Integrating both sides, we have 

`int"e"^-1 "dt" = int "d"x`

⇒ `-"e"^"t"` = x + c

⇒ `-"e"^(-(x + y)` = x + c

⇒`(-1)/"e"^(x + y)` = x + c

⇒ (x + c)ex + y = –1

Hence, the required solution is (x + c).ex + y + 1 = 0.

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Chapter 9: Differential Equations - Exercise [Page 193]

APPEARS IN

NCERT Exemplar Mathematics [English] Class 12
Chapter 9 Differential Equations
Exercise | Q 7 | Page 193

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