Find the angle θ in the unit circle where the sum of sin(θ) and cos(θ) equals 15
To find the angle $ \theta $ where the sum of $ \sin(\theta) $ and $ \cos(\theta) $ equals 1.5, we start with the equation:
$$ \sin(\theta) + \cos(\theta) = 1.5 $$
We can use the Pythagorean identity:
$$ \sin^2(\theta) + \cos^2(\theta) = 1 $$
Let’s square both sides of the original equation:
$$ (\sin(\theta) + \cos(\theta))^2 = 1.5^2 $$
This gives us:
$$ \sin^2(\theta) + 2\sin(\theta)\cos(\theta) + \cos^2(\theta) = 2.25 $$
Using the Pythagorean identity:
$$ 1 + 2\sin(\theta)\cos(\theta) = 2.25 $$
Therefore:
$$ 2\sin(\theta)\cos(\theta) = 1.25 $$
Which simplifies to:
$$ \sin(2\theta) = 1.25 $$
However, we know that the range of $ \sin(2\theta) $ is between -1 and 1, so no such $ \theta $ exists.