From b7f931d7cdb8f022126654ccfc2e0781e55957eb Mon Sep 17 00:00:00 2001 From: Andrew Lorimer Date: Thu, 4 Apr 2019 12:31:57 +1100 Subject: [PATCH] [spec] start antidifferentiation revision --- spec/calculus.md | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) diff --git a/spec/calculus.md b/spec/calculus.md index c239084..167a7e7 100644 --- a/spec/calculus.md +++ b/spec/calculus.md @@ -207,13 +207,23 @@ Order of polynomial $n$th derivative decrements each time the derivative is take ![](graphics/second-derivatives.png) +## Implicit Differentiation + +On CAS: Action $\rightarrow$ Calculation $\rightarrow$ `impDiff(y^2+ax=5, x, y)`. Returns $y^\prime= \dots$. + +Used for differentiating circles etc. + +If $p$ and $q$ are expressions in $x$ and $y$ such that $p=q$, for all $x$ nd $y$, then: + +$${dp \over dx} = {dq \over dx} \quad \text{and} \quad {dp \over dy} = {dq \over dy}$$ + ## Antidifferentiation $$y={x^{n+1} \over n+1} + c$$ ## Integration -$$\int f(x) dx = F(x) + c$$ +$$\int f(x) dx = F(x) + c \quad \text{where } F^\prime(x) = f(x)$$ - area enclosed by curves - $+c$ should be shown on each step without $\int$ @@ -240,6 +250,10 @@ $\int k f(x) dx = k \int f(x) dx$ | ${1 \over {ax+b}}$ | ${1 \over a} \log_e (ax+b) + c$ | | $(ax+b)^n$ | ${1 \over {a(n+1)}}(ax+b)^{n-1} + c$ | +### Definite integrals + +$$\int_a^b f(x) \cdot dx = [F(x)]_a^b=F(b)-F(a)_{}$$ + ## Applications of antidifferentiation - $x$-intercepts of $y=f(x)$ identify $x$-coordinates of stationary points on $y=F(x)$ @@ -269,16 +283,3 @@ $$f(x) = {P(x) \over Q(x)} \quad \text{where } P, Q \text{ are polynomial functi - when two graphs have the same ordinate, $y$-coordinate is double the ordinate - when two graphs have opposite ordinates, $y$-coordinate is 0 i.e. ($x$-intercept) - when one of the ordinates is 0, the resulting ordinate is equal to the other ordinate - - -## Implicit Differentiation - -On CAS: Action $\rightarrow$ Calculation $\rightarrow$ `impDiff(y^2+ax=5, x, y)`. Returns $y^\prime= \dots$. - -Used for differentiating circles etc. - -If $p$ and $q$ are expressions in $x$ and $y$ such that $p=q$, for all $x$ nd $y$, then: - -$${dp \over dx} = {dq \over dx} \quad \text{and} \quad {dp \over dy} = {dq \over dy}$$ - - -- 2.43.2