हिंदी

Show that the line abxa+yb = 1, touches the curve y = b · e– x/a at the point where the curve intersects the axis of y - Mathematics

Advertisements
Advertisements

प्रश्न

Show that the line `x/"a" + y/"b"` = 1, touches the curve y = b · e– x/a at the point where the curve intersects the axis of y

योग

उत्तर

Given that y = b · e– x/a, the equation of curve and `x/"a" + y/"b"` = 1, the equation of line.

Let the coordinates of the point where the curve intersects the y-axis be (0, y1)

Now differentiating y = b · e– x/a both sides w.r.t. x, we get

`"dy"/"dx" = "b" * "e"^((-x)/"a") (- 1/"a")`

= `- "b"/"a" * "e"^((-x)/"a")`

So, the slope of the tangent, m1 = `- "b"/"a" * "e"^((-x)/"a")`

Differentiating `x/"a" + y/"b"` = 1 both sides w.r.t. x, we get

`1/"a" + 1/"b" * "dy"/"dx"` = 0

So, the slope of the line, m2 = ` (-"b")/"a"`.

If the line touches the curve, then m1 = m2

⇒ `(-"b")/"a" * "e"^((-x)/"a") = (-"b")/"a"`

⇒ `"e"^((-x)/"a")` = 1

⇒ `(-x)/"a" log "e"` = log 1  .....(Taking log on both sides)

⇒ `(-x)/"a"` = 0

⇒ x = 0

Putting x = 0 in equation y = `"b" * "e"^((-x)/"a")`

⇒ y = b · e0 = b

Hence, the given equation of curve intersects at (0, b) i.e. on y-axis.

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 6: Application Of Derivatives - Exercise [पृष्ठ १३६]

APPEARS IN

एनसीईआरटी एक्झांप्लर Mathematics [English] Class 12
अध्याय 6 Application Of Derivatives
Exercise | Q 19 | पृष्ठ १३६

वीडियो ट्यूटोरियलVIEW ALL [3]

संबंधित प्रश्न

Find the equation of the normal at a point on the curve x2 = 4y which passes through the point (1, 2). Also find the equation of the corresponding tangent.


Find the equation of tangents to the curve y= x3 + 2x – 4, which are perpendicular to line x + 14y + 3 = 0.


Find the equation of all lines having slope −1 that are tangents to the curve  `y = 1/(x -1), x != 1`


Find the equations of the tangent and normal to the given curves at the indicated points:

y = x2 at (0, 0)


Find the equation of the normal to curve y2 = 4x at the point (1, 2).


Find the slope of the tangent and the normal to the following curve at the indicted point \[y = \sqrt{x} \text { at }x = 9\] ?


Find the points on the curve y = x3 − 2x2 − 2x at which the tangent lines are parallel to the line y = 2x− 3 ?


Find the points on the curve \[\frac{x^2}{4} + \frac{y^2}{25} = 1\] at which the tangent is parallel to the x-axis ?


Find the equation of the tangent and the normal to the following curve at the indicated point\[\frac{x^2}{a^2} + \frac{y^2}{b^2} = 1 \text{ at }\left( a\cos\theta, b\sin\theta \right)\] ?


Find the equation of the tangent and the normal to the following curve at the indicated point  \[x^\frac{2}{3} + y^\frac{2}{3}\] = 2 at (1, 1) ?


Find the equation of the tangent and the normal to the following curve at the indicated point 4x2 + 9y2 = 36 at (3cosθ, 2sinθ) ?    


Find the equation of the tangent and the normal to the following curve at the indicated points x = a(θ + sinθ), y = a(1 − cosθ) at θ ?


Find the angle of intersection of the following curve \[\frac{x^2}{a^2} + \frac{y^2}{b^2} = 1\] and x2 + y2 = ab ?


Find the point on the curve y = x2 − 2x + 3, where the tangent is parallel to x-axis ?


Find the slope of the normal at the point 't' on the curve \[x = \frac{1}{t}, y = t\] ?


Write the equation of the normal to the curve y = x + sin x cos x at \[x = \frac{\pi}{2}\] ?


The point on the curve y2 = x where tangent makes 45° angle with x-axis is ______________ .


The angle of intersection of the curves xy = a2 and x2 − y2 = 2a2 is ______________ .


The slope of the tangent to the curve x = 3t2 + 1, y = t3 −1 at x = 1 is ___________ .


Find the condition for the curves `x^2/"a"^2 - y^2/"b"^2` = 1; xy = c2 to interest orthogonally.


Show that the equation of normal at any point on the curve x = 3cos θ – cos3θ, y = 3sinθ – sin3θ is 4 (y cos3θ – x sin3θ) = 3 sin 4θ


The point on the curve y2 = x, where the tangent makes an angle of `pi/4` with x-axis is ______.


Prove that the curves y2 = 4x and x2 + y2 – 6x + 1 = 0 touch each other at the point (1, 2)


The equation of normal to the curve 3x2 – y2 = 8 which is parallel to the line x + 3y = 8 is ______.


`"sin"^"p" theta  "cos"^"q" theta` attains a maximum, when `theta` = ____________.


The Slope of the normal to the curve `y = 2x^2 + 3 sin x` at `x` = 0 is


The slope of the tangentto the curve `x= t^2 + 3t - 8, y = 2t^2 - 2t - 5` at the point `(2, -1)` is


If (a, b), (c, d) are points on the curve 9y2 = x3 where the normal makes equal intercepts on the axes, then the value of a + b + c + d is ______.


If β is one of the angles between the normals to the ellipse, x2 + 3y2 = 9 at the points `(3cosθ, sqrt(3) sinθ)` and `(-3sinθ, sqrt(3) cos θ); θ ∈(0, π/2)`; then `(2 cot β)/(sin 2θ)` is equal to ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×