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If x = t . log t, y = tt, then show that dydxydydx-y=0 - Mathematics and Statistics

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प्रश्न

If x = t . log t, y = tt, then show that `"dy"/"dx" - "y" = 0`

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उत्तर

x = t . log t       

Differentiating both sides w.r.t. t

`dx/dt=td/dt(logt)+logtd/dt(t)`

= `txx1/t+logt(1)`

`dx/dt=1+logt`             ...(i)

y = tt

Taking logarithm of both sides 

logy = logtt

logy = t.logt

Differentiating both sides w.r.t. t

`1/yxxdy/dt=td/dt(logt)+logtd/dt(t)`

= `txx1/t+logt(1)`

= 1 + logt

`dy/dt=y(1+logt)`     ...(ii)

`dy/dx=(dy/dt)/(dx/dt)`

= `(y(1+logt))/((1+logt))`     ...[From (i) & (ii)]

∴ `dy/dx=y`

∴ `dy/dx-y=0`

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  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 3: Differentiation - EXERCISE 3.5 [पृष्ठ ९७]

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बालभारती Mathematics and Statistics 1 (Commerce) [English] 12 Standard HSC Maharashtra State Board
अध्याय 3 Differentiation
EXERCISE 3.5 | Q 3. 3) | पृष्ठ ९७

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