Formulas for Derivatives of Exponential Functionsmayaj/m142_Chapter4_Sec4.4complet… · 4 Spring...

5
Section 4.4 Derivatives of Exponential and Logarithmic Functions Formulas for Derivatives of Exponential Functions If f (x)= e x , then f 0 (x)= e x If f (x)= a x , where a 6= 0 is any real number, then f 0 (x)= a x · ln a If f (x)= e g(x) , then f 0 (x)= e g(x) · g 0 (x) If f (x)= a g(x) , then f 0 (x)= a g(x) · g 0 (x) · ln a 1. Find the derivative of the following. (a) f (x)=7 10x (b) f (x)=4 (x 7 +x) (c) y = e (5x 5 -4x) . hee = ex . Cl ) - - , Eat - - - Extra Fess - - = IF mess ' - = and . mass ' . Inna = y mess f ' ( x ) = 7mm . mess ' . he 77 ftp.719.fiol.hr#y=4meesf4xI=4mM.meeslehr4 f4×y=4""".(z×e+Dehr4Jf mass = e y ' = ends . mess ' ylaek×%4×).(zs×4_4)÷

Transcript of Formulas for Derivatives of Exponential Functionsmayaj/m142_Chapter4_Sec4.4complet… · 4 Spring...

Page 1: Formulas for Derivatives of Exponential Functionsmayaj/m142_Chapter4_Sec4.4complet… · 4 Spring 2019, Maya Johnson then = In (x 4×2+435)-In (x '-2) 4 @x¥xztus⑤_④ =. Hx)=2mxt5mCx2t4)-4mCx2_

Section 4.4 Derivatives of Exponential and Logarithmic Functions

Formulas for Derivatives of Exponential Functions

If f(x) = ex, then f 0(x) = ex

If f(x) = ax, where a 6= 0 is any real number, then f 0(x) = ax · ln a

If f(x) = eg(x), then f 0(x) = eg(x) · g0(x)

If f(x) = ag(x), then f 0(x) = ag(x) · g0(x) · ln a

1. Find the derivative of the following.

(a) f(x) = 710x

(b) f(x) = 4(x7+x)

(c) y = e(5x5�4x)

. hee = ex . Cl )- -

,

Eat- - - Extra

Fess - -

=IF mess

'

-

=and .

mass'

. Inna

= ymess

f'( x ) =

7mm . mess'

.he 77

ftp.719.fiol.hr#y=4meesf4xI=4mM.meeslehr4

f4×y=4""".(z×e+Dehr4Jfmass

= e

y'

=ends . mess

'

ylaek×%4×).(zs×4_4)÷

Page 2: Formulas for Derivatives of Exponential Functionsmayaj/m142_Chapter4_Sec4.4complet… · 4 Spring 2019, Maya Johnson then = In (x 4×2+435)-In (x '-2) 4 @x¥xztus⑤_④ =. Hx)=2mxt5mCx2t4)-4mCx2_

(d) f(x) = x4 · 5(x7+2)

(e) f(x) =p5 + 4e4x

Formulas for Derivatives of Logarithmic Functions

If f(x) = ln x, then f 0(x) =1

x

If f(x) = loga x, then f 0(x) =1

x · ln a

If f(x) = ln(g(x)), then f 0(x) =g0(x)

g(x)

If f(x) = loga(g(x)), then f 0(x) =g0(x)

g(x) · ln a

2 Spring 2019, Maya Johnson

."t'

-sues

9¥hit ? ( ¥m5

flickr.sk?tT#s'.x.lu5.x4J= mess

42

Tees

f'ha =

'

z. mess

' " ? mess'

f' I x , a

'zl5t4e49-":( 4e4x .

4)✓ I

f4xl=8l5t4e4×J"?e4xJ

-

-

←extra

-

-

= ¥- ness

Incas )

÷mass . In a

Page 3: Formulas for Derivatives of Exponential Functionsmayaj/m142_Chapter4_Sec4.4complet… · 4 Spring 2019, Maya Johnson then = In (x 4×2+435)-In (x '-2) 4 @x¥xztus⑤_④ =. Hx)=2mxt5mCx2t4)-4mCx2_

2. Find the derivative of the following.

(a) f(x) = log15(7� x4)

(b) g(w) = 3 ln(5 + 4w + w4)

(c) f(x) = (ln(1 + ex))5

(d) f(x) =x5

ln(9x4 + 5)

3 Spring 2019, Maya Johnson

= log, ,

( onees )

f 'Cxs=s7fka=i=3 in L mess )

gunI

3 . #

gi↳=s= mess

'S

Ess

f' ↳ =

5 . mess

".

mess'

ftp.5/lnCltexDT#eyes ,

suit a:÷⇒Hxi¥

Page 4: Formulas for Derivatives of Exponential Functionsmayaj/m142_Chapter4_Sec4.4complet… · 4 Spring 2019, Maya Johnson then = In (x 4×2+435)-In (x '-2) 4 @x¥xztus⑤_④ =. Hx)=2mxt5mCx2t4)-4mCx2_

3. Given F (x) = ln

✓x2(x2 + 4)5

(x2 � 2)4

◆.

(a) Use properties of logarithms to rewrite F (x) in terms of the sum and/or di↵erence of simpler

logarithms. Simplify as far as possible.

(b) Find the derivative of F(x).

4. Find an equation of the tangent line to the curve at the point (1, 1).

y = ln⇣xex

8⌘

4 Spring 2019, Maya Johnson

then = In ( x 4×2+435 ) - In ( x'

- 2)4

=@x¥xztus⑤_④.

Hx)=2mxt5mCx2t4)-4mCx2_IYH-e2-t5.e-4.TW#zfyxzXz

-

⇒ y = heyt

¥78-

⇒ y - lux t ×8 7 y

- I = 9×-9

je'

-

- ly t 8×7 y= 9 x - 9 t I

Slope= ly t

845 = 9-rE;Yy=o

Page 5: Formulas for Derivatives of Exponential Functionsmayaj/m142_Chapter4_Sec4.4complet… · 4 Spring 2019, Maya Johnson then = In (x 4×2+435)-In (x '-2) 4 @x¥xztus⑤_④ =. Hx)=2mxt5mCx2t4)-4mCx2_

5. Determine the value(s) of x for which f 0(x) = 0 for the following function.

f(x) = (9x+ 51)e3x+8

6. If $1, 200 is invested in a savings account o↵ering interest at a rate of 4.5% per year, compounded

continuously, how fast is the balance growing after 7 years? (Round your answer to the nearest

cent.)

5 Spring 2019, Maya Johnson

-3 x +8

(9xt5D#9 t 63×+8 ) ( 3)

fan -

. 9e+7?e¥sDf' ( x ) =3 e

3*8 ( 3 t 9×+51 )± 3 e3xt8( 9 x t 54 ) .

f ' C x ) = 0 ←→ 33*(9×+54)=0

32×+8=10 ⇒ l96t5Y# If-55¥ ⇒ x

- -

Find A'

(7)

A Lt ) =P ert ⇒ A Lt ) =L zoo £045 t

A'

It ) = 1200 . 645 ) . e.045T

V.

⇒ Att ) = 54 e.045T

A' l 7) = 54 e.

0450 =23.99$/yeaafter7yee