Use an identity to find the value of each expression:
sin^2 (π/9)+cos^2 (π/9)
sec^2 23°-tan^2 23°

"standard form:

3x2 + 14x − 10 = 0

solutions based on quadratic formula:

x1   = −14 − √ 142 − 4×3×(−10) /   2×3   = −14 − 2 × √ 79 /   6   ≈ −5.296

x2   = −14 + √ 142 − 4×3×(−10) /   2×3   = −14 + 2 × √ 79 /   6   ≈ 0.629

-1/4 > -1 2/3. -1/4 is greater than -1 2/3 because it is closer to 0 on the number line.