69. Oh yes the memes indeed.
B² = 8b + 84
b² - 8b - 84 = 0
b = <u>-(-8) +/- √((8)² - 4(1)(-84))</u>
2(1)<u>
</u>b = <u>8 +/- √(64 + 336)</u>
2
b = <u>8 +/- √(400)
</u> 2<u>
</u>b = <u>8 +/- 20
</u> 2
b = 4 <u>+</u> 10
b = 4 + 10 b = 4 - 10
b = 14 b = -6
<u />
Although there i no triangle given as the question requires, I am still going to answer because I understand it.
ABC is a right angled triangle. The triangle is 90° at C.
The trigonometric ratio sine is given by, sine = opposite/hypotenuse .
Cosine = adjacent/hypotenuse
So therefore, Sin A = 24/30
= 4/5
Cos A = 18/30
= 3/5
Ln(xy) - 2x =0
slope of the tangent line = derivative of the function
[ln(xy)]' = [2x]'
[1/(xy)] [y + xy'] = 2
y + xy' = 2(xy)
xy' = 2xy - y =y(2x-1)
y' = y(2x-1)/x
Now use x = -1 to find y and after to find y'
ln(xy) = 2x
x=-1
ln(-y) =-2
-y = e^-2
y = - e^-2
y' = [-e^-2][2(-1)-1]/(-1) = [e^-2](-2-1)= [e^-2](-3) = - 3e^-2
Answer: option 6. from the list