(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

I made a thread last week where I had a reasonable idea what was going on in 2 problems last week

this week I have 2 problems where i have NO idea where to start.

Show that the ellipse x^{2}+2 y^{2}=2 and the hyperbola 2 x^{2}-

2 y^{2}=1 intersect at right angles.

What is the first time after 3 o'clock that the hands of the clock are together?

2. Relevant equations

3. The attempt at a solution

1st problem, all I know is that perpendicular lines have similar slopes( dunno how to explain , for example 1 line has slope of 4 , perpendicular has to have a slope of -1/4).

but why does that matter? these are not lines so slopes shouldnt even matter at all, should I use implicit differentiation? even if I do, what for?

2nd problem, dunno how to start, cant even draw a diagram , t.t help!

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# Calculus, derivatives in action

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