Q. 5. The equation of the tangent to the curve y=kx+x6 at the point (−2,−19) is px+qy=c. Find the values of the integers k,p,q and c, where c>0.
Find Derivative: First, we need to find the derivative of y=kx+x6 to get the slope of the tangent at the point (−2,−19).Differentiate y with respect to x: y′=k−x26.
Calculate Slope: Now, plug in the x-coordinate of the point (−2) into the derivative to find the slope of the tangent.y′(−2)=k−(−2)26=k−46=k−1.5.
Point-Slope Form: Since the tangent passes through (−2,−19), we can use the point-slope form of the equation of a line: y−y1=m(x−x1), where m is the slope and (x1,y1) is the point.Substitute m with k−1.5 and (x1,y1) with (−2,−19): y−(−19)=(k−1.5)(x−(−2)).
Simplify Equation: Simplify the equation: y+19=(k−1.5)(x+2).Expand the right side: y+19=kx+2k−1.5x−3.
Rearrange Equation: We need to rearrange the equation to the form px+qy=c. Combine like terms: (k−1.5)x+y=−19−2k+3.
Compare with Standard Form: Now, compare the equation with px+qy=c to find p, q, and c.p=k−1.5, q=1, and c=−19−2k+3.
Find k: We know the point (−2,−19) lies on the curve y=kx+x6, so we can plug it in to find k.−19=k(−2)+−26.
Solve for k: Solve for k: −19=−2k−3. Add 2k to both sides: 2k−19=−3. Add 19 to both sides: 2k=16. Divide by 2: k=8.
Find p,q,c: Now that we have k, we can find p,q, and c.p=k−1.5=8−1.5=6.5, but p must be an integer, so there's a mistake.
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