По формуле приведения можно завменить cos5x на sin(п/2-5x)sin(п/2-5x)-sin15x=02sin(п/2-5x-15x)/2*cos(п/2-5x+15x)/2=02sin(п/4-10x)*cos(п/4+5x)=01)sin(п/4-10x)=0 или 2)cos(п/4+5x)=01)sin(п/4-10x)=0п/4-10x=пk10x=п/4-пkx=п/40-пk/102)cos(п/4+5x)=0п/4+5x=п/2+пk5x=п/4+пk<span>x=п/20+пk/5</span>
Уравнение касательной:
y' = f'(Xo)*(X-Xo) + f(Xo).
y'(X)=f'(ctg(X) = -1 / (sin²(X)).
y'(Xo) = -1 / (sin²(pi/6)) = -1 / ((1/2)²) = -1 / (1/4) = -4.
f(Xo) = ctg(pi/6) = √3.
Подставляем полученные значения:
y' = -4(X - (pi/6)) + √3 =
= -4X + (4*pi/6) + √3 =
= -4X + (2pi/3) + √3 = -4X + <span><span>3.826446</span></span>
A² + 2ab + b² = (a + b)², a<span>² - 2ab + b² = (a - b)²</span>
<span>
1) x</span>² + 8x + 16 = (x + 4)²<span>
2) b</span>² <span>+ 10b + 25 = (b + 5)</span>²<span>
3) a</span>² + 16a + 64 = <span> (a + 8)</span>²<span>
4) a</span>² - 14a + 49 = (a - 7)²<span>
5) x</span>² - 1.2x + 0.36 = (x - 0.6)²
6) y² + 1.8y + 0.81 = (y + 0.9)<span>²</span>
X-5y=2x/2-10y/2
x-5y=x²/x-5xy/x
x-5y=4xy³/4y³-20y^4/4y³
x-5y=(x³-25xy²)/(x²-25y²)-(5x²y-125y³)/(x²-25y²)
1) -2х+1+5(х-2)=-4(3-х)+1
-2x+1+5x-10 = -12+4x+1
3x-9 = 4x-11
4x-3x = 11-9
x = 2
2) (х-5)^2 +(х+4)^2=2х^2
x^2-10x+25 +x^2+8x+16 = 2x^2
-2x+41= 2x^2 - 2x^2
2x = 41
x = 41/2
x =20,5
<span>3) 5+ х/2=3x+6/5
5+ 0,5x =3x +1,2
2,5x = 3,8
x = 3,8/2,5
x = 1,52</span>