Answer:
13.4%
Step-by-step explanation:
Use binomial probability:
P = nCr p^r q^(n-r)
where n is the number of trials,
r is the number of successes,
p is the probability of success,
and q is the probability of failure (1-p).
Here, n = 16, r = 2, p = 0.25, and q = 0.75.
P = ₁₆C₂ (0.25)² (0.75)¹⁶⁻²
P = 120 (0.25)² (0.75)¹⁴
P = 0.134
There is a 13.4% probability that exactly 2 students will withdraw.
Perhaps the most concise way to factor is by "completing the square" which is how the quadratic formula is derived...
x^2+6x+8=0 move constant to other side, subtract 8 from both sides
x^2+6x=-8, halve the linear coefficient, square it, then add that to both sides, in this case (6/2)^2=3^2=9
x^2+6x+9=1 now the left side is a perfect square of the form
(x+3)^2=1 take the square root of both sides
x+3=±√1 subtract 3 from both sides
x=-3±√1
x=-3±1
x=-4 and -2
Since the zeros occur when x=-4 and -2 the factors of the equation are:
(x+2)(x+4)
Answer:
f(x) = sec x. tan x
⇔ f(x) = 1/cosx . cosx/sinx
⇔ f(x) = sin x
+) when f(x) is increasing => sin x increases
=> x will increase
+) f(x) is decreasing => x will decrease
+) f(x) is concave up => x ∈ (-pi/2; 0)
+) f(x) concave down => x ∈ (0; pi/2)
Step-by-step explanation:
