SOLUTION: Your textbook says that the focal length f of a lens is given by the lensmaker's formula 1/f=0.6(1/r1+1/r2) where r1 and r2 are the radii of the two circular surfaces. If those rad

Algebra ->  Trigonometry-basics -> SOLUTION: Your textbook says that the focal length f of a lens is given by the lensmaker's formula 1/f=0.6(1/r1+1/r2) where r1 and r2 are the radii of the two circular surfaces. If those rad      Log On


   

Question 795106: Your textbook says that the focal length f of a lens is given by the lensmaker's formula 1/f=0.6(1/r1+1/r2) where r1 and r2 are the radii of the two circular surfaces. If those radii are 4 and 6 respectively, find f.
A. 3/25
B. 4
C. 16/67
D. 1/4

Found 2 solutions by marksmartuko, Alan3354:
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Answer by Alan3354(69443) About Me  (Show Source):
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Your textbook says that the focal length f of a lens is given by the lensmaker's formula 1/f=0.6(1/r1+1/r2) where r1 and r2 are the radii of the two circular surfaces. If those radii are 4 and 6 respectively, find f.
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1/f=0.6(1/r1+1/r2)
Sub for r1 & r1
1/f=0.6(1/4 + 1/6)
Solve for f