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Čo je (sqrt (5+) sqrt (3)) / (sqrt (3+) sqrt (3+) sqrt (5)) - (sqrt (5-) sqrt (3)) / (sqrt (3+) sqrt (3) sqrt (5))?

2/7 Berieme, A = (sqrt5 + sqrt3) / (sqrt3 + sqrt3 + sqrt5) - (sqrt5-sqrt3) / (sqrt3 + sqrt3-sqrt5) = (sqrt5 + sqrt3) / (2sqrt3 + sqrt5) - (sqrt5 + sqrt3) -sqrt3) / (2sqrt3-sqrt5) = (sqrt5 + sqrt3) / (2sqrt3 + sqrt5) - (sqrt5-sqrt3) / (2sqrt3-sqrt5) = ((sqrt5 + sqrt3) (2sqrt3-sqrt5) - (sqrt5-sqrt3) ) (2sqrt3 + sqrt5)) / ((2sqrt3 + sqrt5) (2sqrt3-sqrt5) = ((2sqrt15-5 + 2 * 3-sqrt15) - (2sqrt15 + 5-2 * 3-sqrt15)) / ((2sqrt15 + 5-2 * 3-sqrt15)) / ((2sqrt3) ^ 2- (sqrt5) ^ 2) = (zrušiť (2sqrt15) -5 + 2 * 3zast. (-Sqrt15) - zrušiť (2sqrt15) -5 + 2 * 3 + zrušiť (sqrt15)) / (12-5) = ( -10 + 12) / 7 = 2/7 Všimnite si, že ak sú
Ako si overujete (tan ^ 2x) / (secx-1) -1 = secx?
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"Ľavá strana" = tan ^ 2x / (secx-1) -1 Použite identitu: cos ^ 2x + sin ^ 2x = 1 => 1 + tan ^ 2x = sec ^ 2x => tan ^ 2x = sec ^ 2x -1 => "Ľavá strana" = (sek ^ 2x-1) / (secx-1) -1 = (zrušiť ((secx-1)) (secx + 1) / zrušiť (sekx-1) -1 => secx + 1-1 = farba (modrá) secx = "Pravá strana"
Ako zjednodušujete (1 / sqrt (a-1) + sqrt (a + 1)) / (1 / sqrt (a + 1) -1 / sqrt (a-1)) div sqrt (a + 1) / ( (a-1) sqrt (a + 1) - (a + 1) sqrt (a-1)), a> 1?

Obrovské matematické formátovanie ...> farba (modrá) (((1 / sqrt (a-1) + sqrt (a + 1)) / (1 / sqrt (a + 1) -1 / sqrt (a-1)) ) / (sqrt (a + 1) / ((a-1) sqrt (a + 1) - (a + 1) sqrt (a-1)) = farba (červená) (((1 / sqrt (a- 1) + sqrt (a + 1)) / ((sqrt (a-1) -sqrt (a + 1)) / (sqrt (a + 1) cdot sqrt (a-1))) / (sqrt (a +1) / (sqrt (a-1) cdot sqrt (a-1) cdot sqrt (a + 1) -sqrt (a + 1) cdot sqrt (a + 1) sqrt (a-1)) = farba ( modrá) (((1 / sqrt (a-1) + sqrt (a + 1)) / ((sqrt (a-1) -sqrt (a + 1)) / (sqrt (a + 1) cdot sqrt (a -1))) / (sqrt (a + 1) / (sqrt (a + 1) cdot sqrt (a-1) (sqrt (a-1) -sqrt (a +