Tutor profile: Keqin C.
=lim4(cos4x)–1)/4x =4lim x-0 (cos(4x)–1)/4x =4(0) =0
1) Consider a standard deck of 52 cards, with 13 each of the four suits: spades, hearts, diamonds, and clubs. Suppose one draws 13 cards without replacement and letXbe the number of hearts in the hand.Find: a)E(X) B))P(X= 3)
By using the method of indicator, we know that The probability of each independent indicator is ¼ and there are 13 draws so the expectation is 13/4 This is hypergeometric so plug into equation we get(13c3)(39c10)/(52c13)
How to factor 4x^2+12x+5
4 can be multiplied by 2 and 2 or 1 and 4, 5 can only be multiple by 1 and 5.and then we look at the middle term of 12. Because all the signs are positive we can only have (2x+5)(2x+1)
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