Question

The line y=5x+b is tangent to the graph y=/x at the point P= (a,/a) Find P and determine b.

Answer 1

P = (1/100 , 1/10)
b = 1/20
Equate both equations. Use the substitution y=/x (/ means square root). Obtain an equation in terms of y. 5y2 - y + b = 0 Use b2 - 4ac = 0 for tangent. You'll get the answer for b then replace in equation, overall 5y2 - y + 1/20 = 0. Use the quadratic formula to solve for y. You'll obtain y = 1/10 as answer. Using the substitution y=/x, x=y2, x = (1/10)2 = 1/100, /x = 1/10. 5y2 and (1/10)2 are ...to the square....5y to the power of 2.