Selesaikan sin^{2}20^{circ}+cos^250^circ+sin20^circcos50^circ=3/4

$$\sin ^ { 2 } 20 ^ { \circ } + \cos ^ { 2 } 50 ^ { \circ } + \sin 20 ^ { \circ } \cos 50 ^ { \circ } = \frac { 3 } { 4 }$$

Tentu sahkan

Langkah Penyelesaian

Evaluate trigonometric functions in the problem

$$0.3420201433256687 ^ {2} + 0.6427876096865394 ^ {2} + 0.3420201433256687 \cdot 0.6427876096865394 = \frac{3}{4}$$

Kira 0.3420201433256687 dikuasakan 2 dan dapatkan 0.11697777844051095979530830215969.

$$0.11697777844051095979530830215969+0.6427876096865394^{2}+0.3420201433256687\times 0.6427876096865394=\frac{3}{4}$$

Kira 0.6427876096865394 dikuasakan 2 dan dapatkan 0.41317591116653492029192554775236.

$$0.11697777844051095979530830215969+0.41317591116653492029192554775236+0.3420201433256687\times 0.6427876096865394=\frac{3}{4}$$

Tambahkan 0.11697777844051095979530830215969 dan 0.41317591116653492029192554775236 untuk dapatkan 0.53015368960704588008723384991205.

$$0.53015368960704588008723384991205+0.3420201433256687\times 0.6427876096865394=\frac{3}{4}$$

Darabkan 0.3420201433256687 dan 0.6427876096865394 untuk mendapatkan 0.21984631039295419598585689389678.

$$0.53015368960704588008723384991205+0.21984631039295419598585689389678=\frac{3}{4}$$

Tambahkan 0.53015368960704588008723384991205 dan 0.21984631039295419598585689389678 untuk dapatkan 0.75000000000000007607309074380883.

$$0.75000000000000007607309074380883=\frac{3}{4}$$

Tukar nombor perpuluhan 0.75000000000000007607309074380883 kepada pecahan \frac{75000000000000007607309074380883}{10000000000}. Kurangkan pecahan \frac{75000000000000007607309074380883}{10000000000} kepada sebutan terendah dengan mengeluarkan dan membatalkan 1.

$$\frac{75000000000000007607309074380883}{100000000000000000000000000000000}=\frac{3}{4}$$

Gandaan sepunya terkecil 100000000000000000000000000000000 dan 4 ialah 100000000000000000000000000000000. Tukar \frac{75000000000000007607309074380883}{100000000000000000000000000000000} dan \frac{3}{4} kepada pecahan dengan penyebut 100000000000000000000000000000000.

$$\frac{75000000000000007607309074380883}{100000000000000000000000000000000}=\frac{75000000000000000000000000000000}{100000000000000000000000000000000}$$

Bandingkan \frac{75000000000000007607309074380883}{100000000000000000000000000000000} dengan \frac{75000000000000000000000000000000}{100000000000000000000000000000000}.

$$\text{false}$$