f(x)=√x-1  g(x)=√3-xF=f+g={√ x-1+√3-x}D(F)={√ x-1+√3-x}⇔{ x≥1, x≤3}⇒ D(F)=[1;3]բ)F=f-g=√x-1-√3-xD(F)={√ x-1+√3-x}⇔{ x≥1, x≤3}⇒ D(F)=[1;3]գ)F=f*g=√ x-1*√3-xD(F)={√ x-1*√3-x}⇔{ x≥1, x<3}⇒ D(F)=[1;3]դ)F=f/g=√ x-1/√3-xD(F)={x-1≥0, 3-x≥0, 3-x≠0⇔{ x≥1, x<3}⇒D(F)=[1;3]215f(x)=1+x² g(x)=1/1-xF=fºgF=1+(1/1-x)²=(1-x)²+1/(1-x)²=1-2x+x²+1/(1-x)²=x²-2x+2/(1-x)² 

91  լրացուցիչx²-3x+2=0             D=9-8=1>0                         … Read more

Դահլիճում կա այնքան շարք, որքան աթոռ կա յուրաքանչյուր շարքում։ Քանի՞ շարք կա դահլիճում, եթե աթոռների ընդհանուր թիվը 400 է։ Եթե… Read more

a=22,5° sina=sin45°/2=√1-cos45°/2=√1-√2/2/2=√2-√2/2/2=√2-√2/4=√2-√2/2 cosa=cos45°/2=√1+cos45°/2=√1+√2/2/2=√2+√2/2/2=√2+√2/4=√2+√2/2 tga=tg45/2=√1-cos45/1cos45=√1-√2/2/1+√2/2=√2-√2/2+√2/2=√2-√2/2+√2=√(2-√2)²/(2+√2)92-√2)=2-√2/√4-2=(2-√2*√2/√2*√2=2(√2-1)/2=√2-1 a=67.5 sin135/2=√-cos135/2=1-(-√2/2)/2=1√2/2/2=√2+√2/2=√2√/4=√2+2/2 cos135/2=√1+cos135/2=√1(-√2/2)/2=1-√2/2/2=√2-√2/2/2=2-√2/4=2-√2/2  

cos(α-β)=cosαcosβ+sinαsinβ cos(α+β)=cosαcosβ-sinαsinβ sin(α-β)=sinαcosβ-cosαsinβ sin(α+β)=sinαcosβ+cosαsinβ tg(α+β)=tgα+tgβ/1-tgαtgβ tg(α-β)=tgα-tgβ/1+tgαtgβ ctg(α+β)=ctgαctgβ-1/ctgα+ctgβ ctg(α-β)=ctgαctgβ+1/ctgα-ctgβ

sin(π/2-α)=cosαtg(π/2-α)=ctgαcos(π/2-α)=sinαctg(α-π)=ctgαtg(α-π)=tgαcos(3/2π-α)=-sinαsin(α-3/2π)=cosαcos(π+α)=-cosα118sinα=210°=-1/2cosα=210°=-√3/2tgα=210°=√3/3ctgα=210°=√3sinα=5/4π=225°=-√2/2cosα=5/4π=225°=-√2/2tgα=5/4π=225°=1ctgα=5/4π=225°=1sinα=4/3π=240°=-√3/2cosα=4/3π=240°=-1/2tgα=4/3π=240°=√3ctgα=4/3π=240°=√3/3119ctg(90°-α)=tgαcos(90°+α)=-sinαsin(270°-α)=-cosαsin(270°+α)=cosαtg(α-270°)=-ctgαctg(α-180°)=ctgα120cos(810°+α)=- sinαcos(990°-α)=- cosαtg(α-450°)=- ctgαtg(7π-α)=-tgα121cos²(3π/2-x)=0+sin²(x)=sin²(x)tg²(π+x)=tg²π+tg²x=tg²xcos4(π-x)=-cos4(x)=cos4x122ա) sin²(180°-α)+sin²(270°-α)=sin²α+(-cos²α)=sin²α+cos²α=1բ) sin(90°-α)+cos(180°+α)+tg(270°-α)+ctg(360°+α)=sin(90°-α)+cos(180°+α)-ctg α+ctg α=0գ) sin(π+α)cos(π/2+α)-cos(2π+α)sin(3π/2-α)=-sin α×(-sin α)-cos α×(-cos α)=sin²α+cos²α=1դ) tg α tg(π/2+α)tg(π+α)tg(3π/2+α)=tg α×(-ctg α)×tg α tg(3π/2+α)=-tgα… Read more

sin2a/sina=2sina*cosa/sina=2cosa sin2a/cos2a=2sinacosa/2cos2a=sina/cosa=tga sin2a/sina-cosa=2sina*cosa/sina-cosa=2cosa-cosa=cosa cos2a-cos2a=cos2a-sin2a-cos2a=-sin2a sin2a+cos2a=sin2a+cos2a-sin2a=cos2a sin2a-cos2a=-(cos2a-sin2a)=-cos2a 2sinπ/12*cosπ/12=sin(2*π/12)=sinπ/6=1/2 cos²15°-sin²15°=cos(2*15)=cos30°=√3/2

106 1.sin²α-cos²α+1/sin²α=sin²α+sin²α/sin²α=2sin²α/sin²α=2 2cos4α-sin4α/sin2α-cos2α=(cos2α-sin2α)(cos2α+sin2α)/sin2α-cos2α=-1(cos2α+sin2α)=-1   3.(cosα+sinα)-2sinαcosα=cos2α+sin2α+2sinαcosα-2sinαcosα-2sinαcosα=cos2α+sin2α=1                              … Read more

cos2a=cos2a-sin2a cos2a=1-2sin2a cos2a=2cos2a-1 sin2a=2sinacosa tg2a=2tga/1-tg2a ctg2a=ctg2a-1/2ctga իջեցման բանձևեր sin2a=1-cos2a/2 cos2a=1+cos2a/2

103.                                       … Read more