Simplify cos(arcsin(( square root of 2)/3))
Problem
Solution
Identify the inner expression as an angle
θ whereθ=arcsin(√(,2)/3) Apply the definition of the inverse sine function, which implies
sin(θ)=√(,2)/3 for−π/2≤θ≤π/2 Use the Pythagorean identity
cos2(θ)+sin2(θ)=1 to find the value ofcos(θ) Substitute the value of
sin(θ) into the identity:cos2(θ)+(√(,2)/3)2=1 Solve for
cos2(θ) by calculating the square:cos2(θ)+2/9=1 Subtract
2/9 from both sides:cos2(θ)=7/9 Take the square root of both sides, noting that
cos(θ) must be positive becauseθ is in the range ofarcsin() which is[−π/2,π/2] cos(θ)=√(,7/9) Simplify the radical expression:
cos(θ)=√(,7)/3
Final Answer
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