Answer:
a solution is 1/2 *tan⁻¹ (2*y) = - tan⁻¹ (x²) + π/4
Step-by-step explanation:
for the equation
(1 + x⁴) dy + x*(1 + 4y²) dx = 0
(1 + x⁴) dy = - x*(1 + 4y²) dx
[1/(1 + 4y²)] dy = [-x/(1 + x⁴)] dx
∫[1/(1 + 4y²)] dy = ∫[-x/(1 + x⁴)] dx
now to solve each integral
I₁= ∫[1/(1 + 4y²)] dy = 1/2 *tan⁻¹ (2*y) + C₁
I₂= ∫[-x/(1 + x⁴)] dx
for u= x² → du=x*dx
I₂= ∫[-x/(1 + x⁴)] dx = -∫[1/(1 + u² )] du = - tan⁻¹ (u) +C₂ = - tan⁻¹ (x²) +C₂
then
1/2 *tan⁻¹ (2*y) = - tan⁻¹ (x²) +C
for y(x=1) = 0
1/2 *tan⁻¹ (2*0) = - tan⁻¹ (1²) +C
since tan⁻¹ (1²) for π/4+ π*N and tan⁻¹ (0) for π*N , we will choose for simplicity N=0 . hen an explicit solution would be
1/2 * 0 = - π/4 + C
C= π/4
therefore
1/2 *tan⁻¹ (2*y) = - tan⁻¹ (x²) + π/4
Answer:
z = 3
Step-by-step explanation:
Since the points are collinear then the slopes between the points are equal.
Calculate the slope m using the slope formula
m = 
with (x₁, y₁ ) = P (2, - 3) and (x₂, y₂ ) = Q (3, - 2)
m = 
= 1
Repeat with
(x₁, y₁ ) = Q (3, - 2) and (x₂, y₂ ) = R (8, z )
m = 
= 
, then
= 1 ( multiply both sides by 5 )
z + 2 = 5 ( subtract 2 from both sides )
z = 3
Answer:
a) Scores of 2 and higher are significantly high
b) Scores of -2 and lower are significantly low
c) Scores between -2 and 2 are not significant.
Step-by-step explanation:
Mean = 0
Standard deviation = 1
a. significantly high (or at least 2 standard deviations above the mean).
2 standard deviations above the mean is:
0 + 1*2 = 2
So scores of 2 and higher are significantly high
b. significantly low (or at least 2 standard deviations below the mean).
2 standard deviations below the mean is:
0 - 1*2 = -2
So scores of -2 and lower are significantly low
c. not significant (or less than 2 standard deviations away from the mean).
2 standard deviations above the mean is:
0 + 1*2 = 2
2 standard deviations below the mean is:
0 - 1*2 = -2
So scores between -2 and 2 are not significant.
Step-by-step explanation:
