"Mutually" with 互相 and 相互
Both adverbs are used almost interchangeably.
Pay attention
The modal adverb (语气副词) expresses subjective judgment or assurance toward an action.
The adverbs 互相 
and 相互 "each other, mutually" are used in a conversation about two or more objects that interact with each other.
and 相互 "each other, mutually" are used in a conversation about two or more objects that interact with each other.Examples
你们先自己互相认识一下吧
You should get to know each other first
nǐmen xiān zìjǐ hùxiāng rènshí yíxià ba
他们互相讨厌
They hate each other
tāmen xiānghù tǎoyàn
两家公司同意相互协作
Both companies have agreed to cooperate with each other
liǎng jiā gōngsī tóngyì xiānghù xiézuò
Pay attention
互相 and 相互 are almost identical in usage, but there is a slight difference in their meaning:
互相 emphasizes the process of interaction, no matter what comes after it.
相互, on the contrary, emphasizes the action that comes after it.
相互 and 互相 can form the following words and phrases:
相互作用
相互支持
互相帮助
互相尊重
相互支持
互相帮助
互相尊重 相互 can also be used as an adjective "mutual". It is usually followed by the particle 的 .
.Examples
这种感觉是相互的
The feeling is mutual
shuāngfāng dōu yuànyì gùjí xiānghù de lìyì
双方都愿意顾及相互的利益
Both sides are willing to take their mutual interests into account
zhè zhǒng gǎnjué shì xiānghù de
Pay attention
互相 cannot be used as an adjective.