Answer:
He did 9 times 10 instead of 9 times 100.
Step-by-step explanation:
3cos2x +sinx=1
3(1-2sin²x)+sinx=1
3-6sin²x+sinx=1
sinx(-6sinx+1)=1
either
sinx=1
sinx=sin(90)
:.x=90
or
-6sinx+1=1
-6sinx=1-1
sinx=0/-6
sinx=sin0,sin180
:.x=0,180and90
please give brainliest
Let's solve your equation step-by-step.
x2+x=12
Step 1: Subtract 12 from both sides.
x2+x−12=12−12
x2+x−12=0
Step 2: Factor left side of equation.
(x−3)(x+4)=0
Step 3: Set factors equal to 0.
x−3=0 or x+4=0
x=3 or x=−4
Answer:
x=3 or x=−4
Using scientific notation, it is found that the measure of one astronomical unit in kilometers is 
A number in <em>scientific notation</em> is given by:

- In which

- To realize the conversion from decimal to scientific notation, b is the number of decimal places the comma moves, being positive if to the left, negative if to the right.
In this problem, 1 AU = 150,000,000 km.
- The comma has to move 8 places to the right, hence

Then, the measure is: 
For more on scientific notation, you can check brainly.com/question/16394306
Answer:
2/3 =x
Step-by-step explanation:
f(x) = 3x - 2
Let f(x) =0
0 = 3x-2
Add 2 to each side
2 = 3x-2+2
2 =3x
Divide by 3
2/3 =3x/3
2/3 =x