Study Flashcards
Why is 3ln(1/2) < 2ln(1/2)?
3ln(1/2) = 3ln(2^-1)=-3ln(2) and 2ln(1/2)=2ln(2^-1)=-2ln(2).
-3ln(2) < -2ln(2)
If a function has a curved top what is the interval?
Closed
An interval is closed when asked to find where a function is increasing/decreasing when
The top is rounded
Why is sin^-1(sin 4π/3) = -π/3?
sin(π-θ)= sin, so:
sin(π-4π/3)=sin(-π/3) which is in the range of sin^-1.
sin(π-θ)= sin, so:
sin(π-4π/3)=sin(-π/3) which is in the range of sin^-1.
sin^-1(sin 4π/3) = -π/3
What does it mean to find a domain where f is one-to-one?
Find where it is defined
Simplify with exponent rules:
√a √b/ √ab
a^1/6 / b^1/12
Find domain:
h(x)=1/ ^4√x^2 -5x
(-∞, 0) U (5, ∞) because x(x-5)>0 is equal to x<0 and x>5
Find domain:
f(x)= √16-x^4 / x^2 -1
[-2,-1)U(-1,1)U(1,2] because x cannot equal +-1 and x<=+-2 which equals -2<=x<=2
If a function is always decreasing, never zero, and f(-2)=1 and f(1)=2, what is the graph?
A piecewise function.
What does cos(-x) equal?
cos(x)
What does sin(-x) equal?
-sin(x)
Equals -sin(x)
sin(-x)
Simplify:
2x(4-x)^-1/2 - 3√4-x = 0
x=12/5 because you put (4-x)^-1/2 under 2x and ass 3√4-x to right side. Then solve for x.
How is this absolute value function solved?:
3|x-4|=10
|x-4|=10/3
Then x-4=10/3 and x-4=-10/3
Simplify:
3x^3/2•y^3 / x^2•y^-1/2
9y^7 / x because you multiply all exponents by 2 first. Then any negative exponents are flipped and solve.
How is this simplified?
√200 - √32
Split into one non-squarable and squarable:
√2 • √100 - √2 • √16
√2 • 10 - √2 • 4
6√2
Evaluate:
y/x - x/y / 1/y - 1/x
- (y+x) because (y+x)(y-x) / x-y =
- (y+x)(x-y) / x-y
How is this evaluated?:
16^-3/4
Equals 1/(16^1/4)^3
1/2^3
1/8
How do you prove:
√x^2 = x
√(-2)^2 = -2 so false
How do you prove:
a^2+b^2=c^2
(1)^2+(2)^2=(3)^2 so false
How do you prove:
√xy
Equals √x•√y
x^1/2 • y^1/2
(xy)^1/2 = √xy so true
If the half-life is 4 days, what is the mass after 16 days?
(1/2)^t/4 where t is days and 4 is half-life
Difference between rational and algebraic equations
Rational has polynomial on numerator AND denominator
Rational has polynomial on
numerator AND denominator