Find the value of:
cos2 60° + sin2 30°
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cos260°+sin230°=(12)2+(12)2=14+14=1+14=24=12\text{cos}^2 60° + \text{sin}^2 30° = \Big(\dfrac{1}{2}\Big)^2 + \Big(\dfrac{1}{2}\Big)^2\\[1em] = \dfrac{1}{4} + \dfrac{1}{4}\\[1em] = \dfrac{1 + 1}{4}\\[1em] = \dfrac{2}{4}\\[1em] = \dfrac{1}{2}cos260°+sin230°=(21)2+(21)2=41+41=41+1=42=21
Hence, cos2 60° + sin2 30° = 12\dfrac{1}{2}21.
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sin 30° cos 30°
tan 30° tan 60°
cosec2 60° - tan2 30°
sin2 30° + cos2 30° + cot2 45°
