•Tehtävä 1

In[1]:=

D[f[g[x]], x] D[f[g[x]], {x, 2}] D[f[g[x]], {x, 3}]

Out[1]=

f^'[g[x]] g^'[x]

Out[2]=

g^'[x]^2 f^''[g[x]] + f^'[g[x]] g^''[x]

Out[3]=

3 g^'[x] f^''[g[x]] g^''[x] + g^'[x]^3 f^(3)[g[x]] + f^'[g[x]] g^(3)[x]

•Tehtävä 2

In[4]:=

lst = Table[D[Tan[x], {x, i}], {i, 1, 20}]

Out[4]=

{Sec[x]^2, 2 Sec[x]^2 Tan[x], 2 Sec[x]^4 + 4 Sec[x]^2 Tan[x]^2, 16 Sec[x]^4 Tan[x] + 8 Sec[x]^ ...  112949304754176 Sec[x]^6 Tan[x]^15 + 137433710592 Sec[x]^4 Tan[x]^17 + 524288 Sec[x]^2 Tan[x]^19}

In[5]:=

lst[[10]]

Out[5]=

353792 Sec[x]^10 Tan[x] + 1841152 Sec[x]^8 Tan[x]^3 + 1304832 Sec[x]^6 Tan[x]^5 + 128512 Sec[x]^4 Tan[x]^7 + 512 Sec[x]^2 Tan[x]^9

In[6]:=

lst[[10]] /. x -> 0

Out[6]=

0

•Tehtävä 3

In[7]:=

deri = D[x == y[x]^3 + y[x]^2 + y[x] + 1, x]

Out[7]=

1 == y^'[x] + 2 y[x] y^'[x] + 3 y[x]^2 y^'[x]

In[8]:=

Solve[deri /. {x -> 0, y[x] -> -1}, y '[0]]

Out[8]=

{{y^'[0] -> 1/2}}

In[9]:=

ParametricPlot[{y^3 + y^2 + y + 1, y}, {y, -2, 2}, PlotRange -> {{-2, 2}, {-2, 2}}, AspectRatio -> Automatic]

[Graphics:HTMLFiles/ratk6_16.gif]

Out[9]=

-Graphics -

•Tehtävä 4

In[10]:=

f[x_] = ArcTan[x] + ArcTan[(1 - x)/(1 + x)]

Out[10]=

ArcTan[x] + ArcTan[(1 - x)/(1 + x)]

In[11]:=

Simplify[D[f[x], x]]

Out[11]=

0

Kuitenkaan funktio ei ole vakio!

In[12]:=

Plot[f[x], {x, -3, 3}, PlotRange -> {-3, 2}]

[Graphics:HTMLFiles/ratk6_23.gif]

Out[12]=

-Graphics -

•Tehtävä 5

In[13]:=

f[x_] = x^4 - 7 x^3 + 11 x^2 + 7 x - 10 ; f1[x_] = D[f[x], x] ; f2[x_] = D[f[x], {x, 2}] ;

In[16]:=

Plot[f[x], {x, -1.5, 5}]

[Graphics:HTMLFiles/ratk6_27.gif]

Out[16]=

-Graphics -

Nollakohdat:

In[17]:=

NSolve[f[x] == 0, x]

Out[17]=

{{x -> -0.9474126424804555`}, {x -> 0.8407256772709844`}, {x -> 3.2858646893272643`}, {x -> 3.820822275882207`}}

Ääriarvopisteet:

In[18]:=

rat2 = Solve[f1[x] == 0, x]

Out[18]=

{{x -> 7/4 + (-189 + 8 i 9069^(1/2))^(1/3)/(4 3^(2/3)) + 59/(4 (3 (-189 + 8 i 9069^(1/2)))^ ...  8 i 9069^(1/2))^(1/3))/(8 3^(2/3)) - (59 (1 + i 3^(1/2)))/(8 (3 (-189 + 8 i 9069^(1/2)))^(1/3))}}

In[19]:=

apist = Table[{x /. rat2[[i]], f[x] /. rat2[[i]]}, {i, 1, 3}] // N

Out[19]=

{{3.5742137985635267`  - 3.3306690738754696`*^-16 i, -0.8788980209096451` + 0.` i}, {1.9295354 ... 374924586228165` - 1.1102230246251565`*^-16 i, -10.949453288874253` - 1.1570987105878513`*^-30 i}}

In[20]:=

% // Chop

Out[20]=

{{3.5742137985635267`, -0.8788980209096451`}, {1.9295354472987547`, 8.035382559783859`}, {-0.25374924586228165`, -10.949453288874253`}}

Käännepisteet:

In[21]:=

rat3 = Solve[f2[x] == 0, x]

Out[21]=

{{x -> 1/12 (21 - 177^(1/2))}, {x -> 1/12 (21 + 177^(1/2))}}

In[22]:=

kpist = Table[{x /. rat3[[i]], f[x] /. rat3[[i]]}, {i, 1, 2}] // N // Chop

Out[22]=

{{0.6413221086958274`, -2.663751686895674`}, {2.8586778913041724`, 3.1568072424512508`}}

•Tehtävä 6

In[23]:=

f[x_] = 2 * x^4 - 12 * x^3 + 7 * x^2 + 41 * x - 3 ; Plot[f[x], {x, -2, 4.5}]

[Graphics:HTMLFiles/ratk6_42.gif]

Out[23]=

-Graphics -

In[24]:=

rat = NSolve[f[x] == 0, x]

Out[24]=

{{x -> -1.478221699418099`}, {x -> 0.07238581732669022`}, {x -> 3.7029179410457043`  - 0.5538870170968553` i}, {x -> 3.7029179410457043`  + 0.5538870170968553` i}}

In[25]:=

Integrate[-f[x], {x, x /. rat[[1]], x /. rat[[2]]}]

Out[25]=

24.65420705546794`

•Tehtävä 7

In[26]:=

f[x_] = Sin[x]^2 ;

Tilavuus:

In[27]:=

Integrate[Pi * f[x]^2, {x, 0, Pi}]

Out[27]=

(3 π^2)/8

In[28]:=

% // N

Out[28]=

3.7011016504085092`

Pinta-ala

In[29]:=

Integrate[2 * Pi * f[x] Sqrt[1 + f '[x]^2], {x, 0, Pi}]

Out[29]=

2 π EllipticE[-1]

In[30]:=

% // N

Out[30]=

12.001505309269428`

In[31]:=

ParametricPlot3D[{x, Sin[x]^2 * Sin[t], Sin[x]^2 * Cos[t]}, {x, 0, Pi}, {t, 0, 2 * Pi}] ;

[Graphics:HTMLFiles/ratk6_58.gif]

•Tehtävä 8

In[32]:=

f[x_] = ArcSin[2 x * Sqrt[1 - x^2]] ; Plot[f[x], {x, -1, 1}, AspectRatio -> Automatic]

[Graphics:HTMLFiles/ratk6_60.gif]

Out[33]=

-Graphics -

Suljetulla välillä jatkuva funktio: ääriarvot saadaan joko päätepisteissä, derivaatan nollakohdissa tai derivaatan epäjatkuvuuskohdissa.

In[34]:=

 f[-1]  f[1]

Out[34]=

0

Out[35]=

0

In[36]:=

f1[x_] = Simplify[D[f[x], x]]      

Out[36]=

(2 - 4 x^2)/((1 - 2 x^2)^2^(1/2) (1 - x^2)^(1/2))

In[37]:=

rat1 = Solve[f1[x] == 0, x]       

Out[37]=

{}

In[38]:=

rat2 = Solve[Denominator[f1[x]] == 0, x]

Out[38]=

{{x -> -1}, {x -> 1}, {x -> -1/2^(1/2)}, {x -> 1/2^(1/2)}}

Pienin arvo ja suurin arvo:

In[39]:=

f[x /. rat2[[3]]] f[x /. rat2[[4]]]

Out[39]=

-π/2

Out[40]=

π/2

•Tehtävä 9

In[41]:=

<< Graphics`ImplicitPlot`

In[42]:=

ImplicitPlot[{y^2 == x, x - y == 3}, {x, 0, 6}]

[Graphics:HTMLFiles/ratk6_76.gif]

Out[42]=

-Graphics -

In[43]:=

In[44]:=

f[y_] = y^2 ; g[y_] = 3 + y ;

In[45]:=

rat = Solve[f[y] == g[y], y]

Out[45]=

{{y -> 1/2 (1 - 13^(1/2))}, {y -> 1/2 (1 + 13^(1/2))}}

In[46]:=

Integrate[g[y] - f[y], {y, y /. rat[[1]], y /. rat[[2]]}]

Out[46]=

(13 13^(1/2))/6

•Tehtävä 10

In[47]:=

f[x_] = -4 x^2 + 40 x - 97 ;

In[48]:=

Plot[f[x], {x, 3.5, 6.5}]

[Graphics:HTMLFiles/ratk6_86.gif]

Out[48]=

-Graphics -

Vaihtoehto 1

In[49]:=

rat1 = Solve[f[x] == 0, x]

Out[49]=

{{x -> 1/2 (10 - 3^(1/2))}, {x -> 1/2 (10 + 3^(1/2))}}

In[50]:=

Integrate[2 * Pi * x * f[x], {x, x /. rat1[[1]], x /. rat1[[2]]}]

Out[50]=

20 3^(1/2) π

Vaihtoehto 2

In[51]:=

rat2 = Solve[y == f[x], x]

Out[51]=

{{x -> 1/2 (10 - (3 - y)^(1/2))}, {x -> 1/2 (10 + (3 - y)^(1/2))}}

In[52]:=

Integrate[Pi * (x /. rat2[[2]])^2 - Pi * (x /. rat2[[1]])^2, {y, 0, 3}]

Out[52]=

20 3^(1/2) π


Converted by Mathematica  (August 26, 2003)