PeiHsin Lin 林培心 🌸
Khan Academy Ambassador & New York Math Circle Instructor

Thanks for catching that, Lynn.

If you think about it in terms of money, two debts put together make an even bigger debt. (3)³  4² =27  16 =27 + (16) = 43 The answer would be 11 if the problem were slightly different. (3)³...

The explicit formula for arithmetic sequences always follows a specific format. The xth term aᵪ is always equal to the first term a₁ plus the common difference d (x  1) times: aᵪ = a₁ + d(x  1) I...

Ah, now we're delving into calculus. If f(x) is restricted to the domain (1,1) and the range (∞,∞), then f⁻¹(x) is restricted to the domain (∞,∞) and the range (1,1). Restriction to the range (...

STEP 1 For a given f(x), set f(x) = y. STEP 2 Isolate x in terms of y. STEP 3 Set x = f⁻¹(y). Note that this process does not always yield a function. Many rational functions are not invertible. If...

Hi Bailey, Use the distributive property in reverse here. Factor out the 3 in both terms of the numerator. 3 ÷ 3 = 1. Any number divided by itself equals 1. The simplified result is just all that's...

Hi Matthew, For help with specific problems, just post your question and the Khan Academy community will try to help you. As for the question you have mentioned: Medicine (M) in milligrams is given...

Hi Max! If I understand correctly, you're asking for a specialized widget for drawing line segments, similar to what's available in MS Paint or Adobe Photoshop. In case they don't implement your fe...

Hi Arnaud, You're right  Math by Subject > Statistics & Probability doesn't link to a regular mission with Mastery Challenges. I've noticed this, too! But Math by Grade > High School does point to...

You're welcome, Alex! 👍

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