Cho hình chóp S. ABCD có đáy là hình vuông cạnh a, đường thẳng SA vuông góc với đáy, đường thẳng SB tạo với mặt đáy góc . Khi đó thể tích khối chóp S. ABCD là

Which themes are portrayed in this excerpt from leo tolstoy’s the death of ivan ilyich? praskovya fedorovna came of a good family, was not bad looking, and had some little property. ivan ilyich might have aspired to a more brilliant match, but even this was good. he had his salary, and she, he hoped, would have an equal income. she was well connected, and was a sweet, pretty, and thoroughly correct young woman. to say that ivan ilyich married because he fell in love with praskovya fedorovna and found that she sympathized with his views of life would be as incorrect as to say that he married because his social circle approved of the match. he was swayed by both these considerations: the marriage gave him personal satisfaction, and at the same time it was considered the right thing by the most highly placed of his associates. so ivan ilyich got married. conforming to social conventions criticism of a middle class lifestyle the destructive impact of loneliness struggling to face reality the necessity of companionship

Draw a tape diagram to represent each situation.for some of the situations,you need to decide what to represent with a variable andre bakes 9 pans of brownies.he donates 7 pans to the school bake sale and keeps the rest to divide equally among his class of 30 students

Prove (a) cosh2(x) − sinh2(x) = 1 and (b) 1 − tanh 2(x) = sech 2(x). solution (a) cosh2(x) − sinh2(x) = ex + e−x 2 2 − 2 = e2x + 2 + e−2x 4 − = 4 = . (b) we start with the identity proved in part (a): cosh2(x) − sinh2(x) = 1. if we divide both sides by cosh2(x), we get 1 − sinh2(x) cosh2(x) = 1 or 1 − tanh 2(x) = .