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292

x/x²-5x+6

x1=2

x2=3

x²-5x+6≠0

x²-5x+6>0

(-∞;2)∪(2;3)∪(3;+∞)

x-2/√x²+x-6

x-2>0

x>2

x+x-6≠0

x1=-3

x2=2x

x²+x-6≠0

3/5√3-x+4√x²+x-2

x²+x-2≥0

D=1+8=9(3)

x1=-1-3/2

-2

x2=-1+3/2=1

3-x≠0

-x≠-3

x≠3

(-∞;2]∪(1;3)

ա) sin47⁰ + sin61⁰ – sin11⁰ – sin25⁰ = cos7⁰

(sin47⁰ – sin25⁰) + (sin61⁰ – sin11⁰) = cos7⁰

sina – sinb = 2cos * (a + b/2) * sin * (a – b/2)

2cos * (47 + 25/2) * sin * (47 – 25/2) + 2cos * (61 + 11/2) * sin * (61 – 11/2)

2cos * (72/2) * sin * (22/2)

բ) sin19⁰ + sin25⁰ + sin31⁰ = 4sin25⁰ cos33⁰ cos27⁰

(sin19⁰ + sin31⁰) + sin25⁰ = 4sin25⁰ cos33⁰ cos27⁰

sina + sinb = 2cos * (a + b/2)

2cos * (19 + 31/2) * sin25⁰

2cos * (50/2) * sin25⁰

գ) sin16⁰ + sin24⁰ + sin40⁰ = 4sin20⁰ cos12⁰ cos8⁰

(sin16⁰ + sin40⁰) + sin24⁰ = 4sin20⁰ cos12⁰ cos8⁰

sina + sinb = 2cos * (a + b/2)

2cos * (16 + 40/2) * sin24⁰

2cos * (56/2) * sin24⁰

Ապացուցել նույնությունը

ա) tg * (a + b) – tga – tgb/tga tg * (a + b) = tgb

բ) tg * (45⁰ + a) – tg * (45⁰ – a)/tg * (45⁰ + a) + tg * (45⁰ – a) = sin2a