Question

Your friend is looking at laptops for college, and is comparing the different screen sizes. Use the diagram and formula below to find the width of the laptop screen. Round your answer to the tenths place. A.w = 16.7 inchesB.w = 9.9 inchesC.w = 8 inchesD.w = 14.4 inches

Answer 1

Given

$d=\sqrt{w^2+h^2}$

Solve for w, as shown below

$\begin{gathered} \Rightarrow d^2=w^2+h^2 \\ \Rightarrow w^2=d^2-h^2 \\ \Rightarrow w=\sqrt{d^2-h^2} \end{gathered}$

Set d=17, h=9 and find w,

$\begin{gathered} d=17,h=9 \\ \Rightarrow w=\sqrt{289-81}=\sqrt{208}=4\sqrt{13}\approx14.4 \end{gathered}$

Thus, the answer is w=14.4in, option D.