Question:
Consider the equation given by the implicit function:
x3+3xy2−5x=2y3−6xy+4a) Find dxdy using implicit differentiation.
b) Determine the slope of the tangent line to the curve at the point (1,1).
c) Find the equation of the tangent line to the curve at the point (1,1).
Answer:
a) To find dxdy using implicit differentiation, we differentiate both sides of the equation with respect to x and apply the chain rule.
Given equation: x3+3xy2−5x=2y3−6xy+4
Differentiating both sides with respect to x, we get:
dxd(x3+3xy2−5x)=dxd(2y3−6xy+4)Using the chain rule and product rule on the left side, and the chain rule on the right side, we obtain:
3x2+3y2⋅dxdy+3y2⋅dxdy−5=6y2⋅dxdy−6x⋅dxdyRearranging the terms, we have:
(3x2+6y2−6y2)⋅dxdy=−5+6x−3x2Simplifying further, we obtain:
3x2⋅dxdy=6x−3x2+5Finally, dividing both sides by 3x2, we get the expression for dxdy:
dxdy=x22x−x2+35b) To find the slope of the tangent line to the curve at the point (1,1), we substitute x=1 and y=1 into the expression dxdy we obtained above.
Substituting x=1 and y=1 into dxdy gives:
dxdy=(1)22(1)−(1)2+35=138=38Therefore, the slope of the tangent line to the curve at the point (1,1) is 38.
c) The equation of a line can be determined using the point-slope form y−y1=m(x−x1), where (x1,y1) is a point on the line and m is the slope of the line.
Using the point (1,1) and the slope 38, we substitute these values into the point-slope form equation:
y−1=38(x−1)Multiplying both sides by 3 to eliminate the fraction, we get:
3y−3=8(x−1)Expanding and rearranging, we obtain the equation of the tangent line:
8x−3y−5=0Therefore, the equation of the tangent line to the curve at the point (1,1) is 8x−3y−5=0.