Answer:
0.25π
Step-by-step explanation:
→ Expand the bracket
4 × cos²Ф = 2
→ Divide both sides by 2
cos²Ф = 0.5
→ Square root both sides
cos Ф = [tex]\frac{\sqrt{2} }{2}[/tex]
→ Inverse cosine [tex]\frac{\sqrt{2} }{2}[/tex]
cos⁻¹ ( [tex]\frac{\sqrt{2} }{2}[/tex] ) = 0.25π
