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:
D. "If the graph of two variables is not a linear function, then the two variables are not directly proportional"
Step-by-step explanation:
The contrapositive of a statement is basically you changing the conditional part of the statement with its result and then finding the negative of both. This is called Contraposition.
So, for the statement given:
"If two variables are directly proportional, then their graph is a linear function."
The contrapositive will be:
"If the graph of two variables is not a linear function, then the two variables are not directly proportional"
Answer:
-2 x -3/2
Step-by-step explanation:
-2 x -3/2
That would equal three, which is more than 2.
<em>Hope that helps! :)</em>
<em></em>
<em>-Aphrodite</em>
Answer in fraction form: -17/4 < x < 11/4
Answer in decimal form: -4.25 < x < 2.75
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Work Shown:
|4x+3| - 9 < 5
|4x+3| < 5+9 .... adding 9 to both sides
|4x+3| < 14
-14 < 4x+3 < 14 .... see note at the bottom
-14-3 < 4x < 14-3 .... subtracting 3 from all sides
-17 < 4x < 11
-17/4 < x < 11/4 .... divide all sides by 4
-4.25 < x < 2.75
This says that x is between -4.25 and 2.75, but x is not equal to either endpoint.
Note: I used the rule that |x| < k becomes -k < x < k where k is a positive real number.