To solve the equation cos2(x)−4sin(x)cos(x)+3sin2(x)=0, we can use trigonometric identities to simplify it and then factor it:
- Use the trigonometric identity sin2(x)+cos2(x)=1 to replace cos2(x) with 1−sin2(x):
(1−sin2(x))−4sin(x)cos(x)+3sin2(x)=0
- Expand (1−sin2(x)) and 3sin2(x):
1−sin2(x)−4sin(x)cos(x)+3sin2(x)=0
- Combine like terms:
1−sin2(x)+3sin2(x)−4sin(x)cos(x)=0
- Simplify the equation further:
1+2sin2(x)−4sin(x)cos(x)=0
- Factor out a 2 from the first two terms:
2sin2(x)−4sin(x)cos(x)+1=0
- Rewrite 2sin2(x) as sin2(x)+sin2(x) and factor by grouping:
(sin2(x)−2sin(x)cos(x)+1)+(sin2(x)−2sin(x)cos(x)+1)=0
- Notice that (sin2(x)−2sin(x)cos(x)+1) can be factored as (sin(x)−1)2:
(sin(x)−1)2+(sin2(x)−2sin(x)cos(x)+1)=0
- Now, you have a quadratic equation in terms of sin(x). Set each term to zero:
sin(x)−1=0 (1st term)
sin2(x)−2sin(x)cos(x)+1=0 (2nd term)
Let's solve each equation separately:
For the 1st term:
sin(x)−1=0
sin(x)=1
This equation has solutions when x=2π+2πn, where n is an integer.
Now, let's solve the 2nd term:
sin2(x)−2sin(x)cos(x)+1=0
This equation can be factored as (sin(x)−cos(x))2=0.
So, sin(x)−cos(x)=0
sin(x)=cos(x)
This equation has solutions when x=4π+πn, where n is an integer.
So, the solutions to the original equation cos2(x)−4sin(x)cos(x)+3sin2(x)=0 are:
- x=2π+2πn (where
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