Posted by andi telaumbanua on Jul 29, 2018 in
Matematika
Tentukanlah turunan pertama dari:
log(xy) = 4y
Jawab:
d/dx(log(xy)) = d/dx(4y
(y + x dy/dx) (1/(xy ln10 ))= 4 dy/dx
y/(xy ln10 )+ (x/(xy ln10 )) dy/dx = 4 dy/dx
dy/dx [x/(xy ln10 ) – 4]= -y/(xy ln10 )
dy/dx=(-y/(xy ln10 ))/(x/(xy ln10 )-4)
dy/dx=(-y/(xy ln10 ))/((x-4xy ln10)/(xy ln10 ))
dy/dx=(-y)/(x – 4 xy ln10 )
Posted by andi telaumbanua on Jul 29, 2018 in
Matematika
Diberikan fungsi f dan g dengan rumus f(x) = 2x + 3 dan g(x) = cos^2 (3x+1).
Tentukan turuna pertama dari: f(x) g(x)
Jawab:
Misalkan :
h(x) = f(x) g(x)
Misalkan:
u = 3x +1
du/dx=3
dan
v = cos u
dv/du=-sin(u)=-sin(3x+1)
dan
g(x) = y = v^2
dy/dv=2v=2cos(u) =2 cos(3x+1)
Sehingga:
g^1 (x)=(du/dx)(dv/du)(dy/dv)=3(-sin(3x+1))(2 cos(3x+1)) =-6sin(3x+1) cos(3x+1)
Sehingga:
h(x) = f(x) g(x)
h^1 (x) = g^1 (x)f(x)+f^1 (x)g(x)
h^1 (x) = [-6 sin(3x+1) cos(3x+1) ][2x+3]+2[cos^2 (3x+1)]
Posted by andi telaumbanua on Jul 29, 2018 in
Matematika
Diberikan fungsi f dan g dengan rumus f(x) = 2x + 3 dan g(x) = cos^2 (3x+1).
Tentukan turunan pertama dari: f(x) + g(x)
Jawab:
Misalkan :
h(x) = f(x) + g(x)
h(x) =2x + 3 +cos^2 (3x+1)
Misalkan:
u = 3x +1
du/dx=3
dan
v = cos u
dv/du=-sin(u) = -sin(3x+1)
dan
g(x) = y = v^2
dy/dv = 2v = 2cos(u) =2 cos(3x+1)
Sehingga:
g^1 (x) = (du/dx)(dv/du)(dy/dv) = 3(-sin(3x+1))(2 cos(3x+1))=-6sin(3x+1) cos(3x+1)
Sehingga:
h(x) = 2x + 3 +cos^2 (3x+1)
h^1(x) = 2 – 6 sin(3x+1) cos(3x+1)
Posted by andi telaumbanua on Jul 29, 2018 in
Matematika
Diberikan fungsi f dan g dengan rumus f(x) = 2x + 3 dan g(x) = cos^2 (3x+1).
Tentukan turuna pertama dari: (g(x))/(f(x)) untuk x≠-2/3
Jawab:
Misalkan: h(x) =(g(x))/(f(x))
Maka: h(x) =(g(x))/(f(x))=(cos^2 (3x+1))/(2x + 3)
Misalkan:
u = 3x +1
du/dx=3
dan
v = cos u
dv/du=-sin(u)=-sin(3x+1)
dan
g(x) = y = v^2
dy/dv=2v=2cos(u)=2 cos(3x+1)
Sehingga:
g^1 (x)=(du/dx)(dv/du)(dy/dv)=3(-sin(3x+1))(2 cos(3x+1))=-6sin(3x+1) cos(3x+1)
Sehingga:
h^1 (x)=(g^1 (x)f(x)-f^1 (x)g(x))/(f(x))^2
h^1 (x)=[(-6 sin(3x+1) cos(3x+1) )(2x + 3)-2cos^2 (3x+1)]/[(2x + 3)^2]
Posted by andi telaumbanua on Jul 29, 2018 in
Matematika
Tentukanlah turunan pertama dari s(x)=(sin(2x))^3x
Jawab:
Misalkan:
y = s(x)=(sin(2x))^3x
maka:
y =(sin(2x))^3x
lny = ln(sin(2x))^3x
lny =3x ln(sin(2x))
Kemudian kedua ruas diturunkan:
d/dx (lny )= d/dx (3x ln(sin(2x)))
(1/y) dy/dx =3 ln(sin(2x)) + 3x 1/sin(2x) d/dx (sin(2x))
(1/y) dy/dx=3 ln(sin(2x)) + 3x 1/sin(2x) 2 cos(2x)
(1/y) dy/dx=3 ln(sin(2x)) + 6x cos(2x)/sin(2x)
(1/y) dy/dx=3 ln(sin(2x)) + 6x cot(2x)
dy/dx=y [3 ln(sin(2x))+ 6x cot(2x)]
Karena: y=(sin(2x))^3x
Maka:
dy/dx=(sin(2x))^3x [3 ln(sin(2x))+ 6x cot(2x)]