Chapter 22 - Differentiation 2 (Pure) Flashcards
what are convex curves?
convex curves are u shaped so has an increasing gradient and in turn a positive second derivative
what is a convex curve?
a convex curve looks like an n shape and has a decreasing gradient and in turn a negative second derivative
what are points of inflection?
a point where a curve changes from concave to convex.
remember f’‘(x)=0 at a point of inflection
what’s the chain rule?
y = f(g(x))
dy/dx = g⁻¹ (x) f⁻¹(g(x))
what’s the connected rate of change rule?
dy/dx = dy / du X du / dx
when is the chain rule used?
the chain rule is used to differentiate composite functions
like f(g(x))
how to differentiation Y= e ^f(x)
Y= e ^f(x) dy/dx = f’(x) e ^ f(x)
how to differentiate Y= ln(x)
Y= ln(x) dy/dx = 1/x
or
dy/dx = f’(x) / f(x)
what do cos and sin x differentiate to?
sin x
cos x
-sin x
- cos x
differentiate down integrate up
btw its a loop :)
what does tan differentiate to?
tan differentiates to sec² x
what’s the product rule? when do you use the product rule?
if Y=uv, dy/dx= u dv/dx + v du/dx
where u and v are functions
when to use the quotient rule?
you use the quotient rule when its a fraction
how to differentiate parametric equations? what is the equation?
dy/dx = dy/dt ÷dx/dt
what is implicit differentiation?
‘implicit differentiation’ is used when an equation is written in the form f(x,y) = g(x,y)
example: y²= xy + x + 2 is implicit
how to do implicit differentiation?
step 1 : differentiate terms in the x only with respect to x
step 2: use the chain rule to differentiate the y only
step 3: use the the product rule to differentiate terms in both x and y
step 4: re arrange to make dy/dx the subject