How many lines are tangential to both the curves

[TONYYEUNG]

Dear All,

Please help me to answer the following question:-

How many lines are tangential to both the curves y=4+x^2 and y=-4-x^2? At what points do these tangents meet these curves?

Best Regards,

Tony

 

[pka]

First graph both curves!
Then look at \(\displaystyle y = \pm 4x.\)
You will see the answer.

 

[tkhunny]

Did you draw the graphs? Do you recognize the parabolas? Two?

 

[TONYYEUNG]

Thank you for your answer. But I still got some serious problem in the Calculus. Anyway, I will ask if I have got the problem.

Thank you.

Tony