Объяснение:
(sin15°)^4+(cos15°)^4=(sin²15°+cos²15°)²-2sin²15°×cos²15°=1-2sin²15°×cos²15°=1-2×sin15°×cos15°×sin15°×cos15=1-2×sin15°×cos15°×2×sin15°×cos15/2=1-(sin30°)²/2=1-(0,5)²/2=1-0,125=0,875
Объяснение:
(sin15°)^4+(cos15°)^4=(sin²15°+cos²15°)²-2sin²15°×cos²15°=1-2sin²15°×cos²15°=1-2×sin15°×cos15°×sin15°×cos15=1-2×sin15°×cos15°×2×sin15°×cos15/2=1-(sin30°)²/2=1-(0,5)²/2=1-0,125=0,875