If the radius of a circle is 8 inches find the radius of a circle whose area is four times as large? Algebra Quadratic Equations and Functions Linear, Exponential, and Quadratic Models 1 Answer seph Nov 7, 2015 16 inches Explanation: #A = pi * r^2# #=> A = pi * 8^2# #=> A = 64pi# #A' = 4A# #A' = pi * r'2# #pi * r'^2 = 4(64pi)# #=> r'^2 = 256# #=> r' = 16# Answer link Related questions What is the linear regression line? How do you determine if the following data set is linear or quadratic: (-4,10), (-3,7), (-2,4),... How do you know if the following data set is exponential: (0,120), (1, 180), (2, 270), (3, 405)? How do you use the graphing calculator to find the linear regression line? How do you find the best function that models: (-3, 14), (-2, 4), (-1, -2), (0, -4), (1, -2)? If the same amount is added to one dimensions and removed from the other, the resulting... A child care center has 440 feet of fencing to enclose two adjacent rectangular safe play areas.... How do you write the quadratic equation of the graph with the given points (-3, 4), (1,0), and (-1,-2)? A painter is making a rectangular canvas for her next painting. She wants the legnth of the... Is #f(x)= 3x^2# an exponential function? See all questions in Linear, Exponential, and Quadratic Models Impact of this question 2723 views around the world You can reuse this answer Creative Commons License