हिंदी

Find dydx if y = xx+(7x-1)x - Mathematics and Statistics

Advertisements
Advertisements

प्रश्न

Find `"dy"/"dx"` if y = `"x"^"x" + ("7x" - 1)^"x"`

योग
Advertisements

उत्तर

y = `"x"^"x" + ("7x" - 1)^"x"`

Let u = xx  and v = `("7x" - 1)^"x"`

∴ y = u + v

Differentiating both sides w.r.t.x, we get

`"dy"/"dx" = "du"/"dx" + "dv"/"dx"` ....(i)

Now, u = xx 

Taking logarithm of both sides, we get

log u = log(xx)

∴ log u = x. log x

Differentiating both sides w.r.t.x, we get

`1/"u" * "du"/"dx" = "x" * "d"/"dx" (log "x") + log "x" * "d"/"dx"`(x)

`= "x" * 1/"x" + log "x"  *` (1)

∴ `1/"u" * "du"/"dx"` = 1 + log x

∴ `"du"/"dx"` = u(1 + log x) 

∴ `"d"/"dx" ("x"^"x") = "x"^"x"`(1 + log x)    ....(ii)

Also, v = (7x – 1)x

Taking logarithm of both sides, we get

log v = log(7x - 1)x

∴ log v = x. log(7x – 1)

Differentiating both sides w.r.t.x, we get

`1/"v" * "dv"/"dx" = "x" * "d"/"dx" log ("7x" - 1) + log ("7x" - 1) * "d"/"dx"`(x)

`= "x" * 1/("7x" - 1) * "d"/"dx" (7"x" - 1) + log (7"x" - 1) * (1)`

∴ `1/"v" * "dv"/"dx" = "x"/(7"x" - 1) (7 - 0) + log (7"x" - 1)`

∴ `"dv"/"dx" = "v"["7x"/(7"x" - 1) + log(7"x" - 1)]`

∴`"dv"/"dx" = (7"x" - 1)^"x" ["7x"/(7"x" - 1) + log(7"x" - 1)]`      ....(iii)

Substituting (ii) and (iii) in (i), we get

`"dy"/"dx" = "x"^"x" (1 + log "x") + (7"x" - 1)^"x" [log(7"x" - 1) + "7x"/(7"x" - 1)]`

shaalaa.com
The Concept of Derivative - Derivatives of Logarithmic Functions
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 3: Differentiation - MISCELLANEOUS EXERCISE - 3 [पृष्ठ १००]

APPEARS IN

बालभारती Mathematics and Statistics 1 (Commerce) [English] Standard 12 Maharashtra State Board
अध्याय 3 Differentiation
MISCELLANEOUS EXERCISE - 3 | Q IV] 9) | पृष्ठ १००

संबंधित प्रश्न

Find `"dy"/"dx"`if, y = `"x"^("x"^"2x")`


Find `"dy"/"dx"`if, y = `"x"^("e"^"x")`


Find `"dy"/"dx"`if, y = `"e"^("x"^"x")`


Find `"dy"/"dx"`if, y = `root(3)(("3x" - 1)/(("2x + 3")(5 - "x")^2))`


Find `"dy"/"dx"`if, y = `(log "x"^"x") + "x"^(log "x")`


Fill in the Blank

If 0 = log(xy) + a, then `"dy"/"dx" =  (-"y")/square`


Fill in the blank.

If x = t log t and y = tt, then `"dy"/"dx"` = ____


State whether the following is True or False:

If y = e2, then `"dy"/"dx" = 2"e"`


Solve the following:

If y = [log(log(logx))]2, find `"dy"/"dx"`


Differentiate log (1 + x2) with respect to ax.


If u = ex and v = loge x, then `("du")/("dv")` is ______


State whether the following statement is True or False:

If y = log(log x), then `("d"y)/("d"x)` = logx


State whether the following statement is True or False:

If y = 4x, then `("d"y)/("d"x)` = 4x  


Find `("d"y)/("d"x)`, if y = [log(log(logx))]2 


Find `(dy)/(dx)`, if xy = yx 


If x = t.logt, y = tt, then show that `("d"y)/("d"x)` = tt 


Find `("d"y)/("d"x)`, if y = `x^(x^x)`


Find `("d"y)/("d"x)`, if y = `root(3)(((3x - 1))/((2x + 3)(5 - x)^2)`


Solve the following differential equations:

x2ydx – (x3 – y3)dy = 0


If y = x . log x then `dy/dx` = ______.


Find `dy/dx  "if",  y = x^(e^x)`


Find `dy/dx` if, y = `x^(e^x)`


Find `dy/dx, "if"  y=sqrt((2x+3)^5/((3x-1)^3(5x-2)))`


Find `dy/dx,"if"  y=x^x+(logx)^x`


Find `dy/dx` if, `y = x^(e^x)`


Find `dy/dx "if", y = x^(e^x)`


Find `dy/(dx)` if, `y = x^(e^x)`


Find `dy/(dx)` if, `x = e^(3t),  y = e^sqrtt`.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×