हिंदी

Find the equation of tangent to the curve y = x2 + 4x at the point whose ordinate is – 3

Advertisements
Advertisements

प्रश्न

Find the equation of tangent to the curve y = x2 + 4x at the point whose ordinate is – 3

योग
Advertisements

उत्तर

Equation of the curve is y = x2 + 4x    ......(i)

Differentiating w.r.t. x, we get

`("d"y)/("d"x)` = 2x + 4

y = – 3    ......[Given]

Putting the value of y in (i), we get

– 3 = x2 + 4x

∴ x2 + 4x + 3 = 0

∴ x = – 1 or x = – 3

For x = – 1, y = (– 1)2 + 4(– 1) = – 3

∴ Point is (x, y) = (– 1, – 3)

Slope of tangent at (– 1, – 3) is `("d"y)/("d"x)` = 2(– 1) + 4 = 2

∴ Equation of tangent at (– 1,– 3) is 

y + 3 = 2(x + 1)

∴ y + 3 = 2x + 2

∴ 2x – y – 1 = 0

For x = – 3, y = (– 3)2 + 4(– 3) = – 3

∴ Point is (x, y) = (– 3, – 3)

Slope of tangent at (– 3, – 3) is `("d"y)/("d"x)` = 2(– 3) + 4 = – 2

Equation of tangent at (– 3, – 3) is

y + 3 = – 2(x + 3)

∴ y + 3 = – 2x – 6

∴ 2x + y + 9 = 0

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 1.4: Applications of Derivatives - Q.5

संबंधित प्रश्न

Find the derivative of the following function from first principle.

x3 – 27


Find the derivative of the following function from first principle.

`1/x^2`


Find the derivative of the following function from first principle.

`(x+1)/(x -1)`


Find the derivative of the following function from first principle:

(–x)–1


Find the derivative of the following function from first principle: 

sin (x + 1)


Find the equations of tangent and normal to the curve y = x2 + 5 where the tangent is parallel to the line 4x − y + 1 = 0.


Find the equations of tangent and normal to the curve y = 3x2 - 3x - 5 where the tangent is parallel to the line 3x − y + 1 = 0.


Choose the correct alternative.

The equation of tangent to the curve y = x2 + 4x + 1 at (-1, -2) is 


Choose the correct alternative.

The equation of tangent to the curve x2 + y2 = 5 where the tangent is parallel to the line 2x – y + 1 = 0 are


Choose the correct alternative.

If elasticity of demand η = 1, then demand is


Fill in the blank:

If f(x) = x - 3x2 + 3x - 100, x ∈ R then f''(x) is ______


Find the equation of tangent and normal to the following curve.

xy = c2 at `("ct", "c"/"t")` where t is parameter.


Find the equation of tangent and normal to the following curve.

x = `1/"t",  "y" = "t" - 1/"t"`,  at t = 2


Find the equation of tangent and normal to the following curve.

y = x3 - x2 - 1 at the point whose abscissa is -2.


Find the equation of normal to the curve y = `sqrt(x - 3)` which is perpendicular to the line 6x + 3y – 4 = 0.


The slope of the tangent to the curve x = `1/"t"`, y = `"t" - 1/"t"`, at t = 2 is ______


Find the equations of tangent and normal to the curve y = 3x2 – x + 1 at the point (1, 3) on it


Find the equation of tangent to the curve x2 + y2 = 5, where the tangent is parallel to the line 2x – y + 1 = 0


Slope of the tangent to the curve y = 6 – x2 at (2, 2) is ______.


Find the equation of tangent and normal to the curve y = x2 + 5 where the tangent is parallel to the line 4x – y + 1 = 0.


y = ae2x + be-3x is a solution of D.E. `(d^2y)/dx^2 + dy/dx + by = 0`


Find the equations of tangent and normal to the curve y = 6 - x2 where the normal is parallel to the line x - 4y + 3 = 0


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×