145%
200/200: 100%
90/200= 45%
tan2x*cotx - 3 = 0
We know that: tan2x = sin2x/cos2x and cotx = cosx/sinx
==> sin2x/cos2x *cosx/sinx = 3
Now we know that sin2x = 2sinx*cosx
==> 2sinxcosx/cos2x * cosx/sinx = 3
Reduce sinx:
==> 2cos^2 x/ cos2x = 3
Now we know that cos2x = 2cos^2 x-1
==> 2cos^2 x/(2cos^2 x -1) = 3
==> 2cos^2 x = 3(2cos^2 x -1)
==> 2cos^2 x = 6cos^2 x - 3
==> -4cos^2 x= -3
==> 4cos^2 x = 3
==> cos^2 x = 3/4
==> cosx = +-sqrt3/ 2
<span>==> x = pi/6, 5pi/6, 7pi/6, and 11pi/6</span>
1/10 of .9 is the same as dividing .9 by 10.
.90 / 10 = .09
.09 is the answer
Answer:
B
Step-by-step explanation:
Answer:
x = - 4 , x = - 3
Step-by-step explanation:
- 7x = x^2 + 12
Take all terms to one side of equation.
x^2 + 7x + 12 = 0
Find which 2 numbers multiply to give 12 and add to give 7.
a × b = 12
a + b = 7
a = 4
b = 3
Split the middle term using these 2 numbers.
x^2 + 4x + 3x + 12 = 0
Factorise each pair of terms separately.
x ( x + 4 ) + 3 ( x + 4 ) = 0
Bring out common factor of ( x + 4 ) and factorise.
( x + 4 ) ( x + 3 ) = 0
Using the Null factor law, make the expressions in each pair of parentheses equal 0.
x + 4 = 0
x = - 4
AND
x + 3 = 0
x = - 3
THEREFORE:
x = - 4 , x = - 3
