मराठी

If X = E Cos 2 T and Y = E Sin 2 T , Prove that D Y D X = − Y Log X X Log Y .

Advertisements
Advertisements

प्रश्न

If `"x" = "e"^(cos2"t")  "and"  "y" = "e"^(sin2"t")`, prove that `(d"y")/(d"x") = - ("y"log"x")/("x"log"y")`.

बेरीज
Advertisements

उत्तर

Here `"x" = "e"^(cos2"t") and  "y"="e"^(sin2"t")`

⇒ `log_"e" "x" = log_"e" ("e"^(cos2"t")) and log_"e" "y" = log_"e"("e"^(sin2"t"))`

⇒ `log_"e" "x" = cos 2"t" log_"e" ("e") and log_"e" "y"=sin 2"t" log_"e" ("e")    ...["As log"_"e" ("e") = 1]`

∴ `log_"e" "x" = cos 2"t" and log_"e" "y" = sin 2"t"`

Squaring and then adding these two equations,

`(log_"e" "x")^2 + (log_"e" "y")^2 = cos^2 2"t" + sin^2 2"t"`

⇒ `(log_"e" "x")^2 + (log_"e" "y")^2 = 1`

⇒ `2(log_"e" "x") xx (1)/("x") + 2(log_"e" "y") xx (1)/("y") xx (d"y")/(d"x") = 0`

∴ `(d)/(d"x") [(log_"e" "x")^2 + (log_"e" "y")^2] = (d)/(d"x")  ...(1)`

⇒ `(log_"e" "y")/("y") xx (d"y")/(d"x") = - (log_"e" "x")/("x")`

∴ `(d"y")/(d"x") = - ("y"log"x")/("x"log"y")`

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
2015-2016 (March) All India Set 1 E

संबंधित प्रश्‍न

Differentiate the following w.r.t. x:

log (cos ex)


Differentiate the following w.r.t. x:

`sqrt(e^(sqrtx))`, x > 0


Differentiate the following w.r.t. x: 

`cos x/log x`, x > 0


Differentiate the following w.r.t. x:

cos (log x + ex), x > 0


Differentiate the function with respect to x:

(log x)log x, x > 1


Using the fact that sin (A + B) = sin A cos B + cos A sin B and the differentiation, obtain the sum formula for cosines.


If xy - yx = ab, find `(dy)/(dx)`.


If x = `e^(x/y)`, then prove that `dy/dx = (x - y)/(xlogx)`.


If y = `(cos x)^((cos x)^((cosx)....oo)`, show that `"dy"/"dx" = (y^2 tanx)/(y log cos x - 1)`


If `"y" = ("x" + sqrt(1 + "x"^2))^"n",  "then" (1 + "x"^2)  ("d"^2 "y")/"dx"^2 + "x" ("dy")/("dx")` is ____________.


If `"y = a"^"x", "b"^(2"x" -1), "then" ("d"^2"y")/"dx"^2` is ____________.


If `sqrt(("x + y")) + sqrt (("y - x")) = "a", "then"  "dy"/"dx" =` ____________.


If `"xy"^2 = "ax"^2 + "bxy" + "y"^2, "then find"  "dy"/"dx"`


The domain of the function defined by f(x) = logx 10 is


Which function is an exponential function?


Which expression gives the quotient rule for logarithms?


Which expression gives the power rule for logarithms?


Which inverse property is valid only for \[x>0\]?


What is the domain of the exponential function \[y=b^x\]?


What is the range of the exponential function \[y=b^x\]?


What is the range of the logarithmic function \[y=\log_b x\]?


The graph of \[y=\log_b x\] is a mirror image of which graph reflected perfectly across \[y=x\]?


If \[y=b^x\], which equivalent logarithmic statement is correct?


Which pair of graphs are reflections of each other about \[y=x\]?


Differentiate \[\cos^{-1}(e^x)\] with respect to \[x\].


Which list contains the main log laws?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×