Posted by andi telaumbanua on Feb 11, 2018 in
Matematika
Carilah turunan pertama dari y = x^√x !
Jawab:
y = x^√x
ln y = ln (x^√x )
ln y = √x ln x
d(ln y)/dx = d(√x )/dx (lnx) + √x ( d(lnx )/dx)
(1/y) dy/dx = 1/(2√x) lnx + √x (1/x)
dy/dx = y[lnx/(2√x) + √x/x]
dimana : y = x^√x
maka: dy/dx=(x^√x )[lnx /(2√x)+√x/x]
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Posted by andi telaumbanua on Feb 11, 2018 in
Matematika
Carilah turunan pertama fungsi f(x) = ln (x^3+ 1) !
Jawab: Gunakan aturan rantai Misalkan:
z = x^3+ 1 Maka : dz/dx=3x^2
y = ln z maka: dy/dz= 1/z= 1/(x^3+ 1)
sehingga:
dy/dx=(dy/dz)(dz/dx)=(1/(x^3+ 1))(3x^2) = (3x^2)/(x^3+ 1)
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Posted by andi telaumbanua on Feb 11, 2018 in
Matematika
Carilah y^’ dari fungsi 1/x+1/y=1!
Jawab : Gunakan metode turunan implisit
1/x+1/y=1
y = x/(x-1)
maka:
(d (1/x+1/y ))/dx = (d(1))/dx
(d(1/x ))/dx+ d(1/y )/dx = (d( 1))/dx
(((0)(x)- (1)(1))/x^2 )+ (((0)(y)-(1)(dy/dx))/y^2 )=0
-1/x^2 – (dy/dx)/y^2 =0
dy/dx= -y^2/x^2
maka:
dy/dx= -(x/(x-1))^2/x^2
dy/dx= -(x^2/(x^2-2x+1))/x^2
dy/dx= -x^2/(x^4-2x^3+ x^2 )
Posted by andi telaumbanua on Feb 11, 2018 in
Matematika
Carilah y^’ dari fungsi xy+2x+3x^2=4 !
Jawab :
Gunakan metode turunan implisit
xy+2x+3x^2=4
y = (4-2x-3x^2)/x
maka:
(d (xy+2x+3x^2 ))/dx = (d(4))/dx
(d( xy))/dx+ d( 2x )/dx+ (d(3x^2))/dx = (d( 4))/dx
[(d( x)/dx)(y)+ (x)(d(y)/dx) ]+ d( 2x )/dx+ (d(3x^2))/dx = (d( 4))/dx
y+x d(y)/dx+ 2+ 6x = 0
x d(y)/dx= -(y+2+6x)
dy/dx=-(y+2+6x)/x
maka∶
dy/dx=(-((4-2x-3x^2)/x)-2-6x)/x
dy/dx=((-((4-2x-3x^2)/x)-2-6x)/x) (x/x)
dy/dx=(-4+2x+3x^2-2x-6x^2)/x^2
dy/dx=(-4-3x^2)/x^2
Posted by andi telaumbanua on Feb 11, 2018 in
Matematika
Carilah y^’ dari fungsi x^3+y^3=1 !
Jawab :
Gunakan metode turunan implisit
(d (x^3+y^3 ))/dx = (d( 1))/dx
(d( x^3))/dx+ (d( y^3))/dx = (d( 1))/dx
(d( x^3))/dx+ (d( y^3 )/dy)(dy/dx) = (d( 1))/dx
3x^2 + (3y^2) ( dy/dx) =0
dy/dx= (-3x^2)/(3y^2 )
dy/dx= – x^2/y^2