# Find the equation of tangent and normal to the curve at the given points on it. 2x2 + 3y2 = 5 at (1, 1) - Mathematics and Statistics

Sum

Find the equation of tangent and normal to the curve at the given points on it.

2x2 + 3y2 = 5 at (1, 1)

#### Solution

Equation of the curve is 2x2 + 3y2 = 5

Differentiating w.r.t. x, we get

4x + 6y *"dy"/"dx" = 0

∴ "dy"/"dx" = (- "4x")/"6y"

∴ Slope of the tangent at (1, 1) is

("dy"/"dx")_((1,1) = (-4(1))/(6(1)) = (-2)/3

∴ Equation of tangent at (a, b) is

y - b = ("dy"/"dx")_(("a, b") (x - a)

Here, (a, b) ≡ (1, 1)

∴ Equation of the tangent at (1, 1) is

(y - 1) = (-2)/3(x - 1)

∴ 3(y - 1) = - 2(x - 1)

∴ 3y - 3 = - 2x + 2

∴ 3y - 3 = - 2x + 2

∴ 2x + 3y - 5 = 0

Slope of the normal at (1, 1) is (-1)/(("dy"/"dx")_((1,1) = 3/2

∴ Equation of normal at (a, b) is

y - b = (-1)/(("dy"/"dx")_(("a","b") (x - a)

∴ Equation of the normal at (1, 1) is

(y - 1) = 3/2(x - 1)

∴ 2y - 2 = 3x - 3

∴ 3x - 2y - 1 = 0

Concept: Introduction of Derivatives
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#### APPEARS IN

Balbharati Mathematics and Statistics 1 (Commerce) 12th Standard HSC Maharashtra State Board
Chapter 4 Applications of Derivatives
Exercise 4.1 | Q 1.2 | Page 105