उत तर:
न च द ख जव ब …
स पष ट करण:
# Cos2A = sqrt2 (क स -स न) #
# => Cos2A (क स + स न) = sqrt2 (क य क ^ 2A-प प ^ 2 ए) #
# => cos2A (cosA + sinA) = sqrt2 cdot cos2A #
# => रद द कर (cos2A) (cosA + sinA) = sqrt2 cdot रद द कर (cos2A #
# => (क स + स न) = sqrt2 #
# => प प ^ 2A + क य क ^ 2A + 2sinAcosA = 2 # द न तरफ स च क
# => 1 + sin2A = 2 #
# => Sin2A = 1 = sin90 ^ @ #
# => 2A = 90 ^ @ #
# => एक = 45 ^ @ # उत तरद त क मदद ल …
धन यव द…
कब
क य ह (sqrt (5+) sqrt (3)) / (sqrt (3+) sqrt (3+) sqrt (5)) - (sqrt (5-) sqrt (3)) / (sqrt (3+) sqrt (3) sqrt (5))?
2/7 हम ल त ह , 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) - (sqrt5 + sqrt3) (2sqrt3-sqrt5) - (sqrt5 + sqrt5) ) (2sqrt3 + sqrt5)) / ((2sqrt3 + sqrt5) (2sqrt3-sqrt5) = ((2sqrt15-5 + 2 * 3-sqrt15) - (2sqrt15 + 5-2 * 3-sqrt15)) ((2sqrt3) ^ 2- (sqrt5) ^ 2) = (रद द कर (2sqrt15) -5 + 2 * 3cancel (-sqrt15) - रद द कर (2sqrt15) -5 + 2 * 3 + रद द (sqrt15) = (12-5) = ( -10 + 12) / 7 = 2/7 ध य न द क , यद भ जक म ह (sqrt3 +
आप क स सरल करत ह (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?
व श ल गण त प र र पण ...> र ग (न ल ) (((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)) = color (ल ल) ((1 / sqrt (a) 1) + sqrt (a + 1)) / ((sqrt (a-1) -sqrt (a + 1)) / (sqrt (a + 1) cdot sqrt (a-1))) / (sqrt ( +1) / (sqrt (a-1) cdot sqrt (a-1) cdot sqrt (a + 1) -sqrt (a + 1) cdot sqrt (a + 1) sqrt (a-1)) (र ग) न ल ) (((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 + 1)) = color (ल ल) ((1 / sqrt (a-1) + sqrt (a + 1)) / ((sq
अभ व यक त क सरल बन ए ?: 1 / (sqrt (144) + sqrt (145)) + 1 / (sqrt (145) + sqrt (146)) + ... + 1 / (sqrt (168) + sqrt (169))
1 पहल न ट क : 1 / (sqrt (n + 1) + sqrt (n)) = (sqrt (n + 1) -sqrt (n)) / ((sqrt (n + 1) + sqrt (n)) () sqrt (n + 1) -sqrt (n)) र ग (सफ द) (1 / (sqrt (n + 1) + sqrt (n)) = (sqrt (n + 1) -sqrt (n)) / () n + 1) -n) र ग (सफ द) (1 / (sqrt (n + 1) + sqrt (n)) = sqrt (n + 1) -sqrt (n) So: 1 / (sqrt (144) +) sqrt (145)) + 1 / (sqrt (145) + sqrt (146)) + ... + 1 / (sqrt (168) + sqrt (169)) = (sqrt (145) -sqrt (144)) + (sqrt (146) -sqrt (145)) + ... + (sqrt (169) -sqrt (168)) = sqrt (169) -sqrt (144) = 13-12 = 1