Posted by andi telaumbanua on Feb 11, 2018 in
Matematika
(a) Carilah dy/dx dari fungsi x^2+ y^2=25
(b) Tentukan persamaan garis singgungnya di titik (3,4)
Jawab:
(a) Gunakan metode turunan implisit
x^2+ y^2=25
maka∶ y= √(2&25- x^2 )
(d ( x^2+ y^2))/dx = (d( 25))/dx
(d( x^2))/dx+ (d( y^2))/dx = (d( 25))/dx
(d( x^2))/dx+ (d( y^2 )/dy)(dy/dx) = (d( 25))/dx
2x + (2y) ( dy/dx) =0
dy/dx= (-2x)/2y
dy/dx= – x/y
maka: dy/dx= – x/√(2&25- x^2 )
(b) Maka : m = – 3/√(2&25- 3^2 ) = – 3/√(2&16) = – 3/4
Maka persamaan garis singgung kurva dititik (3,4) adalah :
y – y_1=m( x- x_1)
y – 4 = – 3/4 ( x-3)
y = – 3/4 x+ 9/4+ 4
y = – 3/4 x + 25/4
atau 4y = – 3x + 25
atau 3x + 4y = 25
Posted by andi telaumbanua on Feb 11, 2018 in
Matematika
Tentukanlah turunan pertama dari setiap fungsi berikut:
(a) f(x) = (x^4+ 3x^2-2)^50
(b) f(x) = (1+ x^4 )^(2/3)
Jawab
(d [ f(x) ]^n)/dx=(n[f(x) ]^(n-1) ) ( f^’ (x))
Maka :
(a).
(d [x^4+ 3x^2-2)^50])/dx=[50(x^4+ 3x^2-2)^49] ( 4x^3+ 6x) = 50( 4x^3+ 6x) (x^4+ 3x^2-2)^49
(b).
(d [(1+ x^4 )^(2/3)] )/dx=[2/3(1+ x^4 )^(-1/3) ] ( 4x^3) = ( 2/(3(1+ x^4 )^(1/3) ) ) ( 4x^3) = (8x^3)/(3(1+ x^4 )^(1/3) ) = (8x^3)/(3√(3&1+ x^4 ))
Posted by andi telaumbanua on Feb 11, 2018 in
Matematika
Tentukanlah turunan pertama : f(θ) = (e )^(sec 3θ) !
Jawab :
d (e)^f(θ)/dx= e^f(θ) d[f(θ) ]/dx
Maka :
d [(e )^(sec 3θ)]/dx= e^(sec 3θ) d( sec 3θ)/dx = e^(sec 3θ) 3 sec 3θ tan 3θ = 3e^(sec 3θ) sec 3θ tan 3θ
Posted by andi telaumbanua on Feb 11, 2018 in
Matematika
Tentukanlah turunan pertama : f(x) = (e )^(sin x) !
Jawab :
d (e)^f(x)/dx= e^(sin x) (d[f(x) ]/dx)
Maka :
d [(e )^(sin x)]/dx= e^(sin x) (d( sin x))/dx = e^(sin x) cos x
Posted by andi telaumbanua on Feb 11, 2018 in
Matematika
Tentukanlah turunan pertaman: f(x) = (x^3- 1)^1000 !
Jawab :
d [ f(x) ]^n/dx=(n[f(x) ]^(n-1) ) ( f^’ (x))
Maka :
d [(x^3- 1)^1000]/dx=(1000[(x^3- 1)]^(1000-1) ) ( 3x^2) = 1000(x^3- 1)^999 ( 3x^2) = 3000x^2 (x^3- 1)^999